Further question: is there much chance of anything working with an older Broadcom driver?
Forgive my interjection into this thread, but it is relevant to me.
I tried some (not all) of the suggestions in the post by That_Random_Guy, but it appears not to have worked. I have read in various places that older Broadcom wi-fi drivers may not be Linux-compatible. Does anybody know more details (or where I can find a list of compatible/incompatible Broadcom drivers), so I know whether it is worth continuing to try on this matter.
[I will edit this post again when I have time to find details of my Broadcom driver (I will follow instructions for posting details as per Lubuntu 20.04 Wi-fi connection issues - #2 by Chris)… it might be a while, so I make this post now in order to hold the thread open for another month]