Looks like Quantum mining pool are still on the old chain wallet, Artax previously underwent a swap with a new ticker (XAX). Any coin still labelled as (ARTX) is no longer Artax. The pool owner just commented in Discord, and has been made aware of the new wallet and projects position.
Artax (XAX) is no longer mineable and is now in motion as master-node/pure pos, and soon to be pure pos only.