I encountered a strange bug/rollback. I raise all the basic characters to tier 12. And I remember how I raised the characters marked in the screenshot to the gold tier.
The other day I discovered that the equipment leveling was reset.
It seems I haven't gone crazy, I even created special squad selections with characters that still need to be leveled up and these characters are not there now.
I couldn't have dreamed this, please check.
Ally code: 681-668-588