First order cant be killed

Also neither DREY lost untargetable

Immortality persisted through additional battles

Rey's second unique.  "If the ally in the leader slot is any version of Kylo Ren, Rey is untargetable until all enemies have taken a turn or are defeated"....................

.................

Whilst in Grand Arena

"Whilst Rey is untargetable due to this ability, First Order allies can't be defeated".

all toons from both teams took turns

Are you sure?  In the video your unmasked Kylo wasn't even close to taking a turn.  Every time he got his TM anywhere near half full, it was removed.  Remember, he has a sort of Retribution.  So, although he was retaliating a lot; he wasn't actually taking a turn.  I can't say for sure that he didn't in the first 3 to 4 minutes, but he definitely didn't during the video.

I honestly think that as this has been reported as a bug incorrectly several times, and that you don't have actual proof that all characters took a turn, you won't get anywhere with it.