Who are you using to cast the spells?
One of the patches got rid of some camp casting shenans, meaning if you cast a concentration spell with a party member and then make them leave the party their concentration will be broken.
It's also possible that this also has a side effect of breaking concentration for active party members when leaving camp.
Though I don't recall having concentration on things like Hex or Hunter's Mark being broken from going to and from camp (However I never paid too much attention to it given how infrequently going to camp and not long resting is)
Have you tried seeing if other concentration spells also exhibit this behaviour to see if it's an overall concentration thing or simply something unique to Elemental Weapon/Magic Weapon (Which can also be removed if a weapon is unequipped for spaghetti code reasons)?
