When moving bigger production lines, like with 60 assemblers, the companions get stuck. They want to build an item in a place, where the deconstruction has hot been done. Their construction lasers just spread out and get stuck. If the player helps by removing the item in the way, the companions get restuck again.

This happens the same way in vanilla factorio, it's not specific to this mod - there are two jobs, deconstruct and construct, and they are either picked at random or from bots/drones far apart. The solution is usually to have enough bots (or drones), or wait until the slower deconstruction job is done.