I had the same issue today in GAC also with a Raddus team which is why I'm posting here instead of creating a new topic.
My ally code is 579855549. I was running Raddus (lead), Jyn, Cassian, Bistan, and K2-SO (Raddus Zetas and Omicron, no other Zetas or Omicrons) with the Defiance Rising datacron which states "Whenever Light Side allies inflict a debuff on an enemy, they deal damage to that enemy equal to 2% of that enemy's Max Health."
My opponent was Emperor Palpatine (lead), Darth Vader, Thrawn, Tarkin, and Wampa (all Zetas and Wampas Omicron).
I had killed Darth Vader and then used Raddus' granted ability, Hope, which killed Emperor Palpatine and Grand Admiral Thrawn and left Wampa at very low health. Wampa then counterattacked and disappeared. I was then unable to take any further action and had to wait for the battle to time out. I assume what happened is that Wampa critically hit on its counterattack, which caused it to gain Expose from Raddus' leader ability, which caused it to take 2% max health damage from the datacron, killing Wampa. And then maybe the game thought Wampa was still alive?
I've used Raddus all during last month's 3v3 (although not with the datacron) and I regularly use him in TW with the datacron and haven't had issues any other time so I thought it might be a very niche interaction that caused the glitch but the original poster seems to have experienced the issue with, as far as I can tell, nothing in common other than using Raddus.
Would definitely appreciate QV team giving the issue another look. @EA_Gunner