diff --git a/packages/insomnia/src/ui/components/base/dropdown/dropdown.tsx b/packages/insomnia/src/ui/components/base/dropdown/dropdown.tsx
index 2d995b601f..152e5b1554 100644
--- a/packages/insomnia/src/ui/components/base/dropdown/dropdown.tsx
+++ b/packages/insomnia/src/ui/components/base/dropdown/dropdown.tsx
@@ -101,11 +101,13 @@ export class Dropdown extends PureComponent<DropdownProps, State> {
         continue;
       }
 
-      const match = fuzzyMatch(newFilter, listItem.textContent);
+      const match = fuzzyMatch(newFilter, listItem.textContent || '');
 
       if (!newFilter || match) {
         const filterIndex = listItem.getAttribute('data-filter-index');
-        filterItems.push(parseInt(filterIndex, 10));
+        if (filterIndex) {
+          filterItems.push(parseInt(filterIndex, 10));
+        }
       }
     }
 
@@ -131,7 +133,9 @@ export class Dropdown extends PureComponent<DropdownProps, State> {
         for (const li of this._dropdownList.querySelectorAll('li')) {
           if (li.hasAttribute('data-filter-index')) {
             const filterIndex = li.getAttribute('data-filter-index');
-            items.push(parseInt(filterIndex, 10));
+            if (filterIndex) {
+              items.push(parseInt(filterIndex, 10));
+            }
           }
         }
       }
diff --git a/packages/insomnia/src/ui/components/editors/body/graph-ql-editor.tsx b/packages/insomnia/src/ui/components/editors/body/graph-ql-editor.tsx
index b5b41a1c9a..dd66ef66d0 100644
--- a/packages/insomnia/src/ui/components/editors/body/graph-ql-editor.tsx
+++ b/packages/insomnia/src/ui/components/editors/body/graph-ql-editor.tsx
@@ -15,7 +15,7 @@ import React, { PureComponent } from 'react';
 import ReactDOM from 'react-dom';
 import { SetRequired } from 'type-fest';
 
-import { AUTOBIND_CFG, CONTENT_TYPE_JSON, DEBOUNCE_MILLIS } from '../../../../common/constants';
+import { AUTOBIND_CFG, CONTENT_TYPE_JSON } from '../../../../common/constants';
 import { database as db } from '../../../../common/database';
 import { hotKeyRefs } from '../../../../common/hotkeys';
 import { executeHotKey } from '../../../../common/hotkeys-listener';
@@ -811,7 +811,6 @@ export class GraphQLEditor extends PureComponent<Props, State> {
             dynamicHeight
             enableNunjucks
             uniquenessKey={uniquenessKey ? uniquenessKey + '::variables' : undefined}
-            debounceMillis={DEBOUNCE_MILLIS * 4}
             manualPrettify={false}
             defaultValue={variables}
             className={className}
diff --git a/packages/insomnia/src/ui/components/markdown-editor.tsx b/packages/insomnia/src/ui/components/markdown-editor.tsx
index 2cb14559a4..c7fb02320b 100644
--- a/packages/insomnia/src/ui/components/markdown-editor.tsx
+++ b/packages/insomnia/src/ui/components/markdown-editor.tsx
@@ -86,7 +86,6 @@ export class MarkdownEditor extends PureComponent<Props, State> {
               enableNunjucks
               mode={mode || 'text/x-markdown'}
               placeholder={placeholder}
-              debounceMillis={300}
               defaultValue={markdown}
               onChange={this._handleChange}
             />
diff --git a/packages/insomnia/src/ui/components/markdown-preview.tsx b/packages/insomnia/src/ui/components/markdown-preview.tsx
index ca0946feaf..59fe8af3c7 100644
--- a/packages/insomnia/src/ui/components/markdown-preview.tsx
+++ b/packages/insomnia/src/ui/components/markdown-preview.tsx
@@ -1,10 +1,7 @@
-import { autoBindMethodsForReact } from 'class-autobind-decorator';
 import classnames from 'classnames';
 import highlight from 'highlight.js/lib/common';
-import React, { FC, PureComponent } from 'react';
-import ReactDOM from 'react-dom';
+import React, { FC, useEffect, useLayoutEffect, useRef, useState } from 'react';
 
-import { AUTOBIND_CFG } from '../../common/constants';
 import { clickLink } from '../../common/electron-helpers';
 import { markdownToHTML } from '../../common/markdown-to-html';
 import { HandleRender } from '../../common/render';
@@ -14,122 +11,60 @@ interface Props {
   markdown: string;
   handleRender?: HandleRender;
   className?: string;
-  debounceMillis?: number;
   heading?: string;
 }
 
-interface State {
-  compiled: string;
-  renderError: string;
-}
+export const MarkdownPreview: FC<Props> = ({ markdown, className, heading }) => {
+  const divRef = useRef<HTMLDivElement>(null);
+  const [compiled, setCompiled] = useState('');
+  const [error, setError] = useState('');
+  const { handleRender } = useGatedNunjucks();
 
-@autoBindMethodsForReact(AUTOBIND_CFG)
-class MarkdownPreviewInternal extends PureComponent<Props, State> {
-  state: State = {
-    compiled: '',
-    renderError: '',
-  };
-
-  _compileTimeout: NodeJS.Timeout | null = null;
-  _preview: HTMLDivElement | null = null;
-
-  /**
-   * Debounce and compile the markdown (won't debounce first render)
-   */
-  _compileMarkdown(markdown: string) {
-    if (this._compileTimeout !== null) {
-      clearTimeout(this._compileTimeout);
-    }
-    this._compileTimeout = setTimeout(
-      async () => {
-        try {
-          const { handleRender } = this.props;
-          const rendered = handleRender ? await handleRender(markdown) : markdown;
-          const compiled = markdownToHTML(rendered);
-          this.setState({
-            compiled,
-            renderError: '',
-          });
-        } catch (err) {
-          this.setState({
-            renderError: err.message,
-            compiled: '',
-          });
-        }
-      },
-      this.state.compiled ? this.props.debounceMillis : 0,
-    );
-  }
-
-  _setPreviewRef(preview: HTMLDivElement) {
-    this._preview = preview;
-  }
-
-  _handleClickLink(event: any) {
-    event.preventDefault();
-    clickLink(event.target.getAttribute('href'));
-  }
-
-  _highlightCodeBlocks() {
-    if (!this._preview) {
+  useEffect(() => {
+    let shouldUpdate = true;
+    const fn = async () => {
+      try {
+        const rendered = handleRender ? await handleRender(markdown) : markdown;
+        const compiled = markdownToHTML(rendered);
+        shouldUpdate && setCompiled(compiled);
+        shouldUpdate && setError('');
+      } catch (err) {
+        shouldUpdate && setCompiled('');
+        shouldUpdate && setError(err.message);
+      }
+    };
+    fn();
+    return () => {
+      shouldUpdate = false;
+    };
+  }, [handleRender, markdown]);
+  useLayoutEffect(() => {
+    if (!divRef.current) {
       return;
     }
-
-    const el = ReactDOM.findDOMNode(this._preview);
-
-    // @ts-expect-error -- TSCONVERSION
-    for (const block of el.querySelectorAll('pre > code')) {
-      highlight.highlightElement(block);
+    for (const block of divRef.current.querySelectorAll('pre > code')) {
+      if (block instanceof HTMLElement) {
+        highlight.highlightElement(block);
+      }
     }
-
-    // @ts-expect-error -- TSCONVERSION
-    for (const a of el.querySelectorAll('a')) {
+    for (const a of divRef.current.querySelectorAll('a')) {
       a.title = `Open ${a.getAttribute('href')} in browser`;
-      a.removeEventListener('click', this._handleClickLink);
-      a.addEventListener('click', this._handleClickLink);
+      a.removeEventListener('click', _handleClickLink);
+      a.addEventListener('click', _handleClickLink);
     }
-  }
+  }, [compiled]);
+  const _handleClickLink = (event: any) => {
+    event.preventDefault();
+    clickLink(event.target.getAttribute('href'));
+  };
 
-  componentWillUnmount() {
-    if (this._compileTimeout !== null) {
-      clearTimeout(this._compileTimeout);
-    }
-  }
-
-  // eslint-disable-next-line camelcase
-  UNSAFE_componentWillMount() {
-    this._compileMarkdown(this.props.markdown);
-  }
-
-  // eslint-disable-next-line camelcase
-  UNSAFE_componentWillReceiveProps(nextProps: Props) {
-    this._compileMarkdown(nextProps.markdown);
-  }
-
-  componentDidUpdate() {
-    this._highlightCodeBlocks();
-  }
-
-  componentDidMount() {
-    this._highlightCodeBlocks();
-  }
-
-  render() {
-    const { className, heading } = this.props;
-    const { compiled, renderError } = this.state;
-    return (
-      <div ref={this._setPreviewRef} className={classnames('markdown-preview', className)}>
-        {renderError && <p className="notice error no-margin">Failed to render: {renderError}</p>}
-        <div className="selectable">
-          {heading ? <h1 className="markdown-preview__content-title">{heading}</h1> : null}
-          <div className="markdown-preview__content" dangerouslySetInnerHTML={{ __html: compiled }} />
-        </div>
+  return (
+    <div ref={divRef} className={classnames('markdown-preview', className)}>
+      {error ? <p className="notice error no-margin">Failed to render: {error}</p> : null}
+      <div className="selectable">
+        {heading ? <h1 className="markdown-preview__content-title">{heading}</h1> : null}
+        <div className="markdown-preview__content" dangerouslySetInnerHTML={{ __html: compiled }} />
       </div>
-    );
-  }
-}
-
-export const MarkdownPreview: FC<Omit<Props, 'handleRender'>> = props => {
-  const { handleRender } = useGatedNunjucks();
-  return <MarkdownPreviewInternal {...props} handleRender={handleRender}/>;
+    </div>
+  );
 };
diff --git a/packages/insomnia/src/ui/components/panes/request-pane.tsx b/packages/insomnia/src/ui/components/panes/request-pane.tsx
index 1e96f1cf30..64d82e594e 100644
--- a/packages/insomnia/src/ui/components/panes/request-pane.tsx
+++ b/packages/insomnia/src/ui/components/panes/request-pane.tsx
@@ -301,7 +301,6 @@ export const RequestPane: FC<Props> = ({
                 <ErrorBoundary errorClassName="font-error pad text-center">
                   <MarkdownPreview
                     heading={request.name}
-                    debounceMillis={1000}
                     markdown={request.description}
                   />
                 </ErrorBoundary>
diff --git a/packages/insomnia/tsconfig.build.json b/packages/insomnia/tsconfig.build.json
index 21bb683e54..dad95363ac 100644
--- a/packages/insomnia/tsconfig.build.json
+++ b/packages/insomnia/tsconfig.build.json
@@ -1,6 +1,7 @@
 {
   "extends": "../../tsconfig.base.json",
   "compilerOptions": {
+    "lib": ["DOM.Iterable"],
     "experimentalDecorators": true,
     "isolatedModules": true,
     "jsx": "react",