Its not a new motherboard (sorry poor wording on my part, I updated the bios).
But annoyingly, it does restore defaults whenever I update and so I did disable secure boot.
It for some reason is trying to boot windows (and I just went and checked, I deleted the windows installation months ago). I’m using the windows drive as a storage drive now
Also the computer can access the drive, but for some weird reason, when I installed windows, it put the windows boot manager on my linux drive.
Now that windows is gone, the comptuer can’t boot into it. But I sitll have a working Endeavour Os installation, that somehow has lost its grub menu with a simple bios update.
Even if I remove the windows boot manager option using “sudo efibootmgr,” it comes back on reboot (though now its Boot 0004 instead of 0001)
I tried removing the boot opiton and then recreating the grub menu on an endeavour OS live usb, but whatever I did, clearly didn’t work.
Edit: I think for right now, given time constraints and other various constraints, I’ll just reinstall Endeavour OS, but for future reference, if someone can give advice on how to rebuild the grub menu, I think I would appreciate it.