Possible Solution: Vaal Factory Bugged Rare Mob

It appears that the Atlas Skill "Twin Threats" is causing the Rare to be bugged under the ground when it is "duplicated". I removed this skill and ran the map. No bug.

I'm not sure this works 100%, but it's worth a try since paying to reset the one Atlas Skill may save your key. The gold to respec replaces itself by just running the map. Also, since the bug has existed for more than 30 days, it's worth a try while we wait.

Keywords: Vaal Factory, Vaal Foundry, Rare mob, Bug, Archer, Stuck, Floor