QGJ omicron stopped to work in GAC?

No, active and no debuffs at all

What was the full team on both sides?

mine was undersized (QGJ+KAM+JKA), as always in the past. Never faced a similar issue.

I more meant the other team.

Was Cara on the other team? And was her AOE the thing that killed QGJ?

Cara was there, it was a full team. Don't remember if actually her AOE killed QGJ

...and the same problem has just been reported to me from another guy from my Guild. Same issue during this GAC

It's hard to say what happened for certain without a video or something more than "trust me bro"

But it might be possible that the damage from Cara killed QGJ, triggering Ani's bonus turn but then removed Ani's TM after that.

I'd have to test it to be sure though.