grub unknown filesystem. dual booting windows and arch linux

Question

Device: Dell xps-15 9510 running latest arch

I dual boot windows and arch using grub bootloader

I restarted my computer yesterday and was put into grub rescue due to unknown filesystem. 'ls' lists all my partitions My efi partition is hd0,gpt1 but I am unable to boot from it due to it apparently having an unknown filesystem. Most users are able to fix this sort of issue at this point by changing the prefix to their efi partition's boot folder, but ALL of the listed partitions contain an unknown filesystem. There is nothing I can do from grub rescue.

My efi partitions still works fine because I am able to boot into windows from the UEFI one-time boot menu.

I plugged in an arch install disk, mounted /dev/nvme0n1p5 (my main arch partition) to /mnt, mounted /dev/nvme0n1p1 (my efi partition) to /mnt/boot/efi. I ran arch-chroot /mnt. Everything works as normal. Navigating to /boot/efi shows that (I think) everything is normal. All of the windows stuff is in there (EFI, FSCK000, etc). There is a grub folder with fonts, grub.cfg, grubenv, ..., x86-64-efi. Everythng looks normal.

However, no matter what I try, I cannot update, install, or probe grub. grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=GRUB yields "grub-install: error: unknown filesystem"

lsblk -f shows that my efi partitions (nvme0n1p1) has FSTYPE: vfat, FSVER: FAT32, has 28.9 available, is 84% full, and is mounted at /boot/efi. All seems normal. All other partitions look normal as well. I can both boot into windows and see all the files in my linux partition.

I do not beleive that I have done anything to cause this issue. I seldom use windows, but was in it a few days ago and updated it. Howver, I have restarted the computer multiple times since then and had none of these issues.

Any ideas?

I would like to continue dual bootaing and I would only consider wiping the drive as a last resort.

#########EDIT 1:

I am (sadly) using UEFI because the new Dell computers do not allow using legacy bios. I will never buy a dell computer again.

Output from fdisk -l

Disk /deu/nume0n1: 476.94 GiB, 512110190592 bytes, 1000215216 sectors
Disk model: Micron 2300 NUMe 512GB
Units: sectors of 1 » 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/0 size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: DA0B0A74-872P-45F4-9040-C37675BDBC36
Device            Start       End           Sectors       Size       Type
/deu/nume0n1p1    2048        391167        389120        190M       Microsoft basic data
/deu/nume0n1p2    391168      653311        262144        128M       Microsoft reserved
/deu/nume0n1p3    653312      450756607     450103296     214.6G     Microsoft basic data
/dev/nume0n1p4    450756608   492701695     41945088      20G        Linux swap
/dev/nume0n1p5    492701696   1000215182    507513487     242G       Linux filesystem

/Disk /deu/sda: 28.91 GiB, 31039324160 bytes, 60623680 sectors
Disk model: USB DISK 3.0
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: Oxbff8ee56
Device      Boot    Start     End         Sectors      Size       Id     Type
/dev/sda1   *       64        1531903     1531840      748M       0      Empty
/dev/sda2           1531904   1691647     159744       78M        ef     EFI (FAT-12/16/32)
(Disk /dev/loop®: 669.16 MiB, 701665280 bytes, 1370440 sectors
(Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/0 size (minimum/optimal): 512 bytes / 512 bytes

Answer 1

I have solved this issue. The solution is not likely to be helpful for a lot of people.

I had to boot into an arch installation disk, mount my root partitition to /mnt, connect to wifi, chroot to /mnt, then update the system. There was a kernel update. After updating and restarting, I was able to reinstall grub just fine. Weird. I still have no idea what caused the initial issue with grub. The whole situation was very strange.

The reason that some of the characters in the fdisk output are weird is because I had to take a picture of my screen and convert the characters to text. It wasn't an actual issue.