Steps to reproduce:
Install Bitwarden extension from Firefox store.
Click Bitwarden extension button in toolbar.
Start typing in any input box.
Press Left or Right arrow keys
Expected behavior:
Cursor should move left or right.
Orion, OS version; hardware type:
Orion: Version 0.99.117-beta (WebKit 614.1.20)
OS: MacOS Monterey v12.5 (M1)
Notes
This can be demonstrated without a Bitwarden account. The initial login / enter your password screen exhibits this behavior.
Once logged in, you can pop the extension contents out to a new window from the dropdown. Cursor keys work as expected there.