Oh, my bad confused Colosseum with Arena/Fighting pit, and yeah, I don't really know what I did or what I didn't, Should I delete all saves and start a new game? Or something, I don't really mind doing that if there is no other way.
Personally, I would tell you to try a new game ( you don't need to delete your old saves). It's a shame because it should work but it's possible something went awry. Since you're on mobile we also can't look deeper into your save as the save import feature doesn't fully work yet ><
