I have been using my 2 4TB G-raid drives without issue for a few years and recently they began to unmount themselves for no reason. Now I cannot even mount them.
Both drives work on my MacBook Pro (with T3/T2 adaptor).
I have a 2nd Apple Monitor connected to the T2 drive on the iMac and it works well.
Suspect a hardware problem on the iMac but can’t figure it out!