1. Assign a shortcut to the “Toggles the Replace >> button on the Find toolbar” command. For now let’s use Alt+Shift+H.
2. Focus on the Find Expressions box.
3. Press Alt+Shift+H to show the Replace >> button (if not yet shown).
4. Press Tab to focus on the Replace box.
5. Alt+Shift+H again to hide the Replace >> button.
6. Alt+Shift+H again won’t show the Replace >> button.
The cause may be lost keyboard focus, and it’s super easy to work around on the user’s side. Still, it’s better to report than to ignore. Thanks. 🙂