Quadro K2200's. one can, one can't hit 4k @ 60hz

How is that possible? Is one a lowbin piece that burned out that capability? I swapped monitors and cables, and it's the same deal.

Check every part number on each one and see if the hardware is the same or different.

i assume you are using dp, likely that card only supports 1x 4k@60Hz at the time.

ya display port, but it can't even do 4k@60Hz.