Question mark because I'm not sure what exactly happened. Not sure if this is a new thing either, but I've never seen it happen before.

I was shaman with someone else on P8 @1984585 and everything appeared to be going well. I spawned on the left and used portals to get myself on top with the rest of the mice. I was done with my platform to the middle when the other guy was done with a platform under the cheese. I moved the blue portal, selected the orange one and what I THINK happened is that we both spawned the orange portal at the exact same time (I saw him spawning as well).

Next thing: The entire room gets transported to 0,0.

Screenshot:

That's strange. o.O

Stuff like this seems to happen occasionally. I noticed that you can provoke it by spawning a circular object (cannon, ball, rune, bloon) between 2 static grounds, although that works rarely and not on all maps (@628530 seemed to work well in its original version). This might've been the case here. Moreover, I've seen multiple cases of people getting this glitch by spawning a cannonball ~100px under the cage in @467414.

... or all this is completely unrelated and portals just freak out the game.

Its a really bad bug. It happens almost everytime there are 2 shams + portals like you said. Its strange.. Tfm really needs to fix it.