Customer decided to plug in their MS Surface DOCK 2 docking station ethernet into the back of the Poly IP 330 phone and it would disable the phone altogether. Previously a desktop computer was attached with no issue. I have never used a Surface tablet or a docking station but not sure why ethernet out would disable the phone?

Maybe LLDP has something to do with it? You could try turning LLDP off on the phone (if that's an option).

How does the phone behave when the dock is plugged in? Does it immediately power off completely?

I once saw a case with Aastra phones back in the day where the cables were reversed - POE switch was plugged into the PC port and the PC was plugged into the network port. Surprisingly, the phone powered up but needless to say there was some strange behavior!

Phone stays powered on but no communication.