I have been noticing that when I invade planets a tile will dissapear and sometimes as many as 7 tiles will disappear.
I believe this has to do with the bug where the PQ doesn't update.
For instance if I invade a PQ11 planet and it actually has 16 tiles, then 5 of those tiles will disappear.
It is really, really annoying. Especially when something really useful is on the planet.