It seems there’s a unintentional bug? not sure, but while playing a new character, some of the story bosses in crystal mines goes to lv. 1, happened to 2-4 of the bosses for me. Going into a new map does not “erase” the bug. But does not seem to be consistently bugged too. Easy few shots kill… didn’t take any screenshot cause i’m still noob.
Before the maintenance, it happened to me to the boss fight at Demon Prison F4. The boss was level 1.