My bet is buggy WiFi NIC drivers trying to work with something that never existed when they were created.
There is a pretty good chance if you look up the manufacturer of the WiFi NIC (such as Intel) and go to their website and grab the latest driver that it will work. You are almost certainly going to have to go to the manufacturer of the WiFi chipset, rather than the manufacturer of the computer containing the WiFi NIC.
You can test this if you really want by disabling 802.11ax under radio profiles as a short-term test - but I would not take away features from 99% of the users to allow 1% of the users to work.
If you find it is 802.11ax, then the users could look at getting a modern USB WiFi dongle and using that, or of course, replacing their very old computers.