Has anyone else experienced an issue with Claymore ZCash Miner v7.0 regarding only one of the GPU's working at half it's strength?

These three rigs are using all
480 8GB Sapphire Nitro+ cards.
All of the Sol/s is great except that one...
I have hard reset, checked all the cables, removed the overclock, and switched the bios yet nothing will budge it.
No matter what I do; I can't bring it up to speed. The lazy swine.
Does anyone have any suggests?