After the last patch, only 1 worker can build the human Town hall at a time at expansions, it seems like you cannot select the Town hall via right click or left click - only drag select.
This bug doesn’t affect any other building; only the town hall. Reproduced 3/3 games, 2 in multiplayer and one vs A.I. Restarted game to make sure. Not sure if just me or other players as well.
This is a very major bug.