I cannot help for the first problem, I do not have it. For the second, I have experienced similar issues and moved to the “Dark Background and Light Text” extension, which works better in my case.

Thank you for your suggestion and the link. The first setting is indeed set to false, but changing the second from true to false does not solve this issue. To be more precise, when Librewolf is not running, clicking a link actually opens it to the foreground. However, when it is already open, it does not come in the foreground.