What would cause a non-boot all of the sudden. No hardware change at all!

[jbarnette]

Ok so this system has been running flawlessly for prolly 6 months to a year.

Specs are
Latest mac OS and latest OC 6.0
Asus TUF z390M pro gaming
i9-9900k
23GB ram and a VEGA 64
SMBIOS iMac Pro 1,1
Intel NVME boot drive. 1TB

Everything was working fine. I had a SATA drive that I needed to install Windows 10 on for someone. So I shutdown the system and removed my NVME drives. and I installed the SATA SSD for the windows 10 install.

I made no changes to the bios. I installed windows from a USB key made by the Microsoft media creation tool. I completed the install and made sure all windows updates we done.

I shutdown the system and I removed the sata drive. and I reinstalled the Intel nVME SSD.

When I booted up though the system keeps going to the bios. no matter what I do. also it keeps deleting the boot order selections. I can go in and I can select the Intel NVME drive as the first boot option. Then save the setting and reset and it will just go right back into the bios.

I can get it to boot from a USB I used to install Mac-OS. It will also boot from the Windows Sata drive if I put that in.
and like I said I can boot the USB then select the Mac OS So the OS and is in intact replaced.

I have since tried replace the EFI with a Backup from last week. I have reset up the bios. I'm at my wits end here I dont know why this will not work

I also have a second NVME in running the bigsur beta and it does the same thing wont boot I'm thinking it has to be something with the ASUS motherboard. I have tried resetting the bios man times and putting the setting back in but nothing works it will always just remove the boot selection reset and go right back into the bios
.

Any insight would be appreciated.

 

[jbarnette]

so weird I have everything booting from a USB using the backup of EFI from about a week ago I put it on a USB drive and plugged that in it will set as boot. evidently the ASUS board doesn't like booting from name is a data drive is detected it will alway remove the name from he boot list and put the windows as the first item no matter how many times I change it. However even with the windows drive disconnected. The system refuses to boot from the EFI on the name drive. the same exact EFI folder but on a USB drive boots just fine. Makes no sense.