Mosaic drivers crashing on restart requiring reinstall of drivers

Hi everyone,

I have 2 Dell Precision 7865 Towers with AMD Ryzen threadripper pro 5945X, 32GB RAM with (2) NVidia A4000 graphics cards installed for 8 total DisplayPort outputs on each PC. We are using 6 of the outputs (4 from one card and 2 from the other) to go to 6 screens. Created 6 screen mosaic array because our presentation runs 1920*6480 (6 screens in portrait mode as one display). Initially we didn’t have NVIDIA Quadro Sync II cards installed but installed them when we started seeing the issues below - but they’re presence doesn’t seem to have any effect on our system.

We can get the mosaic set up and playing our presentation, but upon restart we have issues. The PC takes about 4-5 minutes to post, never loads into windows or launches presentation. We have to power off the machine, pull the graphics cards out, go to onboard graphics with one screen. Trying to launch the nvidia control panel doesn’t work and we have to uninstall/reinstall the drivers, shutdown, reinstall graphics cards, reboot, rebuild mosaic. All of that to have the presentation work fine until the PC needs to reboot/shutdown and everything happens all over.

Our 6 output DP go into a Wolfpackgreen 4k 16x16 HDMI Matrix switcher. From the switcher they go to Extron HDMI over Cat 6 extenders to the displays. Issue with graphics drivers crashing occurs on site with the Matrix switcher and extenders, but also in our test environment running directly to 6 displays. The same issue happens across two PCs. Mosaic appears stable on our onsite display until restart/reboot.

Any help would be appreciated, and I can clarify/add information not present if needed.

Thank you.