I've noticed the characters that carryover from the previous day's Coliseum do not update with the tokens I get from my inbox. You can see in the attached screenshot the borrowed toons I want to use are at era level 64, when the pool of toons to the left are level 65.
It's easy enough to fix in game currently but would be nice not to have to fix it every few days. Could even be just a visual bug for all I know. But if you remove them from the right hand side (the squad) so they enter the pool or toons on the left, you can bring them right back in at the correct era level and do the battle and it will re-save the proper era level going forward until the next upgrade tokens are collected from my inbox and I need to rinse and repeat.
Perhaps it's already on your radar of things to do, and it's not all that urgent given the in-game work around, and the ability to try new squads regularly which to an extent self corrects this issue, but I didn't see a ticket. Thanks.