It does the same thing when using 2 separate artifact buffs the same frame so maybe the game can’t give 2 buffs in the same tick and so it gives the shadowcloaking but not the artifact buff, and since the artifact buff never times out it assumes its still active and doesn't let you use it again?
I think it may be a Skulker claws issue. I'm having the exact same issue when using the fighting fungus with skulker claws but no other weapons are having the same issue
I was using fighting fungus and blight bangle. I used keyboard to hit them at the exact same time