Firefox Add-on in sidebar hangs after launch of browser

If Firefox (92.0.1 (64-bit)) is closed with the add-on visible in the sidebar, the add-on hangs when the browser next launches (see image below). It is necessary to select a different option in the sidebar, e.g. Bookmarks then select Bitwarden to display the login/unlock fields. Otherwise the add-on in the sidebar remains unusable.

Same here. Can’t remember exactly when it started, but it was weeks ago.