Don't applySelection change for off-canvas text length changes

packages/rich-text/src/component/index.js

@@ -151,8 +151,28 @@ export function useRichText( {
 	}
 
 	function applyFromProps() {
+		// Get previous value before updating
+		const previousValue = _valueRef.current;
+
 		setRecordFromProps();
-		applyRecord( recordRef.current );
+
+		// Check if content length changed (text was added/removed, not just formatted)
+		const contentLengthChanged =
+			previousValue &&
+			typeof previousValue === 'string' &&
+			typeof value === 'string' &&
+			previousValue.length !== value.length;
+
+		// Check if focus is on this element
+		const hasFocus = ref.current?.contains(
+			ref.current.ownerDocument.activeElement
+		);
+
+		// Skip re-applying the selection state when content changed from external source
+		// (e.g., typing in sidebar input changes canvas text)
+		const skipSelection = contentLengthChanged && ! hasFocus;
+
+		applyRecord( recordRef.current, { domOnly: skipSelection } );
 	}
 
 	const didMountRef = useRef( false );

test/e2e/specs/editor/blocks/navigation.spec.js

@@ -606,6 +606,93 @@ test.describe( 'Navigation block', () => {
 			await pageUtils.pressKeys( 'ArrowDown' );
 			await expect( navigation.getNavBlockInserter() ).toBeFocused();
 		} );
+
+		test( 'should preserve focus in sidebar text input when typing (@firefox)', async ( {
+			page,
+			editor,
+			requestUtils,
+			pageUtils,
+		} ) => {
+			// Create a navigation menu with one link
+			const createdMenu = await requestUtils.createNavigationMenu( {
+				title: 'Test Menu',
+				content: `<!-- wp:navigation-link {"label":"Home","url":"https://example.com"} /-->`,
+			} );
+
+			// Insert the navigation block
+			await editor.insertBlock( {
+				name: 'core/navigation',
+				attributes: {
+					ref: createdMenu?.id,
+				},
+			} );
+
+			// Click on the navigation link label in the canvas to edit it
+			const linkLabel = editor.canvas.getByRole( 'textbox', {
+				name: 'Navigation link text',
+			} );
+			await linkLabel.click();
+			await pageUtils.pressKeys( 'primary+a' );
+			await page.keyboard.type( 'Updated Home' );
+
+			// Open the document settings sidebar
+			await editor.openDocumentSettingsSidebar();
+
+			// Tab to the sidebar settings panel
+			// First tab should go to the settings sidebar
+			await page.keyboard.press( 'Tab' );
+
+			// Find the text input in the sidebar
+			const textInput = page.getByRole( 'textbox', {
+				name: 'Text',
+			} );
+
+			// Tab until we reach the Text field in the sidebar
+			// This may take multiple tabs depending on other controls
+			for ( let i = 0; i < 10; i++ ) {
+				const focusedElement = await page.evaluate( () => {
+					const el = document.activeElement;
+					return {
+						tagName: el?.tagName,
+						label:
+							el?.getAttribute( 'aria-label' ) ||
+							el?.labels?.[ 0 ]?.textContent,
+						id: el?.id,
+					};
+				} );
+
+				if (
+					focusedElement.label?.includes( 'Text' ) &&
+					focusedElement.tagName === 'INPUT'
+				) {
+					break;
+				}
+
+				await page.keyboard.press( 'Tab' );
+			}
+
+			await expect( textInput ).toBeFocused();
+			await pageUtils.pressKeys( 'ArrowRight' );
+			// Type in the sidebar text input
+			await page.keyboard.type( ' Extra' );
+
+			// Verify the text was actually typed (change happened)
+			await expect( textInput ).toHaveValue( 'Updated Home Extra' );
+
+			// Tab again to move to the next field
+			await page.keyboard.press( 'Tab' );
+
+			// Check that focus is still within the document sidebar
+			const focusIsInSidebar = await page.evaluate( () => {
+				const activeEl = document.activeElement;
+				const sidebar = document.querySelector(
+					'.interface-interface-skeleton__sidebar'
+				);
+				return sidebar?.contains( activeEl );
+			} );
+
+			expect( focusIsInSidebar ).toBe( true );
+		} );
 	} );
 
 	test( 'Adding new links to a navigation block with existing inner blocks triggers creation of a single Navigation Menu', async ( {