I too have not had any success getting my broadcom wireless to work with 5.0.1, where it worked flawlessly with 4.0.2.

I just saw a note in a different forum (quantian, which is a knoppix derivative) that may shed some light from a little different perspective.

The bottom line to the comment was that there was a gcc incompatibility between the kernel (5.0.1 version) and some of the modules / drivers that was causing the modules to not work.

The note went on to say that they took specific steps to rebuild the modules explicitly specifying gcc 3.3, and life was good after that.

Now, in my case, I did check the broadcom bcm43xx driver and strings bcm43xx.ko | grep -i gcc reports that the gcc used there was version 4.0. I am thinking that I might dive in and work through that, when I get a little more time.

This may well not be your specific problem, but perhaps worth a quick look.

Best Regards,