IIUC, it's not a bug, it's intended behavior.
Found some documentation here:
https://download.nvidia.com/XFree86/...anagement.html
"Since the amount of system memory available to drivers at suspend time is often insufficient to accommodate large copies of video memory, the NVIDIA kernel drivers are designed to act conservatively, and normally only save essential video memory allocations.
The resulting loss of video memory contents is partially compensated for by the user-space NVIDIA drivers, and by some applications, but can lead to failures such as rendering corruption and application crashes upon exit from power management cycles."
I don't know if this (and other sites) imply the GPU is _incapable_ of keeping power to memory during suspend (maybe it can't get its volts from the mobo until wake time?).
Just trying to parse that doc to figure out what I need to do. IMHO it should be saving all VRam by default, GPU<->Memory speeds are huge so it doesn't take long to save/restore even if every single bit is used.