I tried doing CSM disabled, and the BIOS automatically re-enabled it at boot, because the graphics card=Sapphire HD 7970 Dual X would not work. I appreciate all of your help. I think I will have to give up on the idea of a fast-boot Ubuntu NVMe option. I’m still using the NVMe as the “Home” in Ubuntu, so it’s still a good use. I’m actually glad that thanks to Ubuntu I’m able to keep using this veteran PC from 2012!