I’ve been having the same problem for quite some time with the last few OS versions. I’m currently on 0S 3.8.0 without any other problems. I’ve downloaded FF again just now and it still won’t/ can’t connect to the internet.
Screenshot from 2020-05-14 09-03-09|690x389
I think this problem is more widespread than is thought. Here’s my diagnostic file.
eos-diagnostic-200514_085907_UTC 0700.txt (1.4 MB)
Hope this helps in your search for a solution.
Cheers.
Jack75