That is not “the linux store”.
Thats discover. And the only way it is going to be able to manage your (pacman) packages is through packagekit (you may note packagekit-qt6 among the optional dependencies) - which is inherently buggy and unsecure.
You should not be trying to use discover as a package manager.
( For widgets or themes OK - the capabilities it already has. )
There is nothing ‘wrong’ here.
PS.
If you need a GUI package manager then the only recommendation is octopi.
Which is a graphical wrapper for pacman and optionally supported aur-helpers.
Not bauh. Not pamac. Not discover. Just octopi.