After some limit cards from Support zone are moved into Graveyard

[inbrain]

I'm unsure is it a part of rules or a bug (tried to google it first and search through forums but didn't find anything relevant)

In one of my practice games I had Rita, Shadow Priestess in my support zone and most of here tokens upon creation were moved into graveyard. Also some of my other cards appeared on graveyard while I'm 100% sure they were not killed by a removal or some property of a card.
Does anyone have any insight on why it should behave this way?

[Heart]

possible bug, report through the bug report and send in an output log and as much info. Try to recreate the scenario if you can also

[Pjoelj]

Currently in a game against Puffy with over 500 characters in my support zone. Haven't had this happen yet.

Do you have a rough idea how many characters you had in support when this started happening?

[chaosangel2112]

Was something in play causing their life to drain?  A previously played acid rain or something with a blanket -2 health?

[inbrain]

No there were no acid rain played. Also not only creatures moved to graveyard but 1 artefact. I had 1 token creature generator card the name of which I don't remember as I don't have it in my collection (she generates 1 token 2/2 each turn and can suc a creature for 5 life). Together with Orion, Master Acrhitect, which I also used for generating new creatures
I didn't observe anything like this afterwards, so might be my lack of experience in the game to recognise what really killed them. But I never played the same combination of cards either