Had a nasty problem with Zimonja today -- haven't really checked on it since before I upgraded to 3.3.0, so I dropped in to see what level the city was. By appearances, it looked to be at at least level 2 (walls were up). Codsworth is the original city leader, but when I checked the desk, it said the city was level 0, and showed Mr. Sommerville as the leader. Rebuilding the local data corrected that, but now the city showed as 0 with no leader. Re-assigned Codsworth, and the only options I got were to build the city from scratch.
Note that I only recently got Sommerville as a settlement (like, yesterday RL), and I'm building it manually, so I haven't set a city leader there yet.