When I open a URL in a tab in a Profile, I see that cookies are applied accordingly. When I do a fetch request with {"credentials":"include"}
in the extension background page in a Profile, the cookies are not sent in the request. This, however, works when doing it in the normal "Personal Profile".
Cookies are not applied in fetch request in the extension background page when executed in a Profile
The same situation applies to me here.
This is might be related with my issue. https://forums.developer.apple.com/forums/thread/764279
I have similar problem (which is in popup.js) and also using another profile.