Challenge dungeons (medals problem)

So i got a problem that from date when they relesed challenges, got on few gold medals. Now on some characters they reset daily and on some they don't reset at all. Like 2-3 weeks can't do the dungeon. I mean i can but w/o valors :)
Any1 has any idea how to fix it?
Made ticket but gm didn't want to help me (reset it or whatever).

VP are given only for doing challange mode for the first time , they are not rested daily or weekly.

then why every1 else can farm it daily xD

They do it on other alts , but also you can do it over and over to get better times ofc

nah man, medals resets daily for some ppl, not on other alts.