Greetings Raybeze!
As far as i know the dungeons (outside of glowing mushrooms) do not reset and there is no means of which to get them to. It may be worth looking into some of the mods available on nexus etc?

just keep in mind every player will have to have them installed too.

If there is no mod to reset dungeons might i suggest using the shared map/map marker mod (Valheim Plus) and just ask people to X out the completed ones?
I get it isn't the droid you are looking for but at the very least you won't be jumping into completed dungeons.