! many other threads like this one
bcmwl-kernel-source broken on kernel: 5.8.0-34-generic
didn't solve my issue with Broadcome wifi disappeared after updates. !
Here is a very straightforward decision.
My name is Vladimir and I have found the decision that worked for my case. So, on my Ubuntu 20.04 on HP 250G laptop with Broadcom BCM43xxxx wireless device wifi had disappeared after updating/upgrading (January 2021). After 3 days of searches and dozens of errors gotten, I have found this cure:
apt purge bcmwl-kernel-source
apt-get install broadcom-sta-source
apt-get install broadcom-sta-dkms
apt-get install broadcom-sta-common
Thanks to joaorami (joaomppr) from https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/1878045
