As I play a lot of hunts on low level characters and noticed that the Gear Score / Difficulty is sometimes messed up: In this screenshot, a L27 seems to have advanced against enemies, which are “very hard” with a GS of 3,156 
I managed to find the cause of the problem. It seems that internally, the difficulty setting for Season Battles (both in active season and in the archive) and Hunt are linked together. This means, that they are also linked across multiple characters and interfere with active hunts and new hunts.
Important: This does not impact the real enemy or reward level.
To reproduce, first check the current difficulty set for Season Battles. Please note that Difficulty VII leads to a GS of 3,156:
Now switch to the Hunt screen and check the different hunts I’ve started already. Note that it is not possible to use Difficulty VII unless the character is already L50:
Now switch back to the Season Battles screen and change the difficulty all the way down to Easy. Please note that I’ve done this with my L50, so the new enemy score is 1,203:
And back to the Hunt screen we go:
So with the difficulty, which scales with the level, the displayed values also change