Toypocalypse sucks you right back in
The same happened to me but with Bell Choir, I spawned back just on the portal to it and entered the instance again. Luckily it didn’t happened again on the 2nd attempt.
I routinely have to leave Snowball Mayhem 2 or 3 times because I re-enter the world on top of the door and get put right back in.
An option is to get in through the NPC instead the portal, this way you will be put back near the NPC instead near the portal. Just a workaround, I know.
And for completeness’ sake, I have that happen when I leave the jumping puzzle. The second time usually works fine.
In fact it happens for all the Wintersday activity if you use the portal to start it.