Open Source and Free Software

I remember on a couple upgrades that Broadcom had issues with a hardware vs. software block in a config file that even if your external wifi switch is turned on (laptop) the file has wifi harware set to block. In that file you just unblock both hardware and software. You have the choice of either. There is also a terminal command to do the same. These are all root commands/text not local user.
I'm on my phone now but I'll look it up when I'm on my main machine. In the mean time maybe that gives you something to search.

Try...
sudo rfkill list all

See if your network hardware is listed and if it's blocked.

If anything is blocked then..

sudo rfkill unblock all

or

sudo rfkill unblock (whatever the name of the hardware is)

Broadcom also has issues with other loaded drivers. An installed driver may need to be blacklisted in /etc/modprobe.d/blacklist.conf