When using it together with Heartstone (having the item in the hotbar or in the hand) the whole bar vanishes(is invisible.
https://modrinth.com/mod/heartstone

Playing on Fabric 1.21.1

Artifacts Mod also breaks - the magnet for example is also invisible.

I cannot replicate either of these issues, they must be caused by an interaction with another mod in your installation. In a fresh installation with just Heartstone, Artifacts & AutoHUD, everything appears to work perfectly fine. If you could try to reduce the mods you have installed and figure out which mods are required for this issue to appear, that would be very helpful.

So i tested my client mods & found the culprit :)
Its palladium, not sure why but with this one in my modpack it breaks
https://modrinth.com/mod/mpalladium