Hi dibl
I haven't upgraded my EEEpc (which runs LXqt) in a couple of days, and still have wifi and connman. When I run apt update and apt full-upgrade nothing is removed (I'm not going any further till this is resolved). There is a library that is updated named "libnm0" that is related to network manager, I don't know if this is the cause of the problem, but, there doesn't seem to be anything else on the update list that would affect network manager.
Tom