When fighting in the arena, sometimes an opponent team will show a different character after examining a character's detail page and  then returning to the "vs" page. This doesn't happen on every opponent, but when it does it happens when you examine the details of any of the opposing team.

Steps to reproduce: open the arena.In this example I have selected Missylee's team.

You can see Missylee's team here in the "vs" page:

I then check one of the opponents. It doesn't matter which one, but in this case I selected Aristocrat:

I then close the details page, and return to the "vs" page. Note the change to Sinesha from Ritualist:

If you click on Sinesha's icon you get Sinesha's detail page; when you close that, you return to the incorrect team lineup on the "vs" page.

When you close the "vs" page, you return to the Arena list, and the opposing team is again correct. Re-opening the battle "vs" page shows the correct team, but the same bug happens if you repeat the steps.

Reproducible: I have reproduced this on multiple occasions over the last 2 weeks; I can't say for sure when I first saw it. However, it doesn't happen on every opponent team. As far as I can tell the effect is random.

I just did another test: I got new opponents, and one was a singleton uncommon. The bug reappeared for the Flamenel team, but not the others:

Battle screen:

and the incorrect champion after clicking details on Sniper, shows Grinner instead: