My sparky lxqt install had the network seize up, stopped, after a connman update. Rolling back with dpkg did not seem to do the trick.
Evidently https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=813647 connman: daemon no longer starts after upgrade
Similar is #813580 But what I found was funny was #742408 "We want connman 1.22. And then I realized why this did not impact me in sid(uction)-unstable lxqt - I am at 1.31-6 there.
Reviewing "apt-cache showpkg connman" in siduction shows that there are two versions. Debian is still at 1.21 and is having problems finding a mentor to push forward. Someone at siduction seems to be pushing the connman development along in the debian testing-unstable world.
I am in process of converting to doing my networking via systemd so I am not going to be looking much more into this.
peace out,