"Welcome to GRUB!" after CPU change

[Sawtaytoes]

I just changed my CPU from the Epyc 7252p to the Epyc 7313p. The system boots, but it eventually lands on the "Welcome to GRUB!" screen, but there are no boot options available:

All I did before this happened was change the CPU. Does the OS need to be reinstalled when changing the CPU? Was it that my UEFI settings got reset? I didn't see anything specifically changed.

I'm on the latest TrueNAS SCALE at this time. I'd tell you which, but I can't boot to find out.

 

[Sawtaytoes]

This is my boot order:

My boot drives are still there, so I don't think that's the issue:

 

[Sawtaytoes]

Looks like it reset my UEFI. Yeah... That's super weird.

I don't remember that happening on any of my client PCs, but that was the issue.

I switched the boot mode to both Legacy and UEFI because I'm assuming that's the issue. UEFI boot should work though.

This is the GNU GRUB screen I saw this time:

It finally booted!

What's the trick to UEFI boot?