Resized NixOS partition. Why is boot partition ext4 and root fat32?

#1

I just resized my NixOS partition using Gparted LiveCD. It was reporting that my boot partition was ext4, but my NixOS partition was fat32. I remember it being the other way around when I installed NixOS.

After resizing (shrinking) the NixOS partition, NixOS fails to boot.

UPDATE: I rebooted Gparted Live CD, and now the boot partition is displayed as fat32, while the NixOS partition is ext4. I’m not sure how they got transposed last time. Also, this time there was a warning symbol next to the boot partition. I ran a disk repair from Gparted, and it seems to have gone away.

UPDATE: I just closed the Gparted program and re-opened it, now there are warning symbols on the root and swap partitions. What is going on?

The warning reads:

e2label: No such file or directory while trying to open /dev/nvme0n1p1
Couldn't find valid filesystem superblock.
Couldn't find valid filesystem superblock.
dumpe2fs 1.45.0 (6 Mar-2019)
dumpe2fs: No such file or directory while trying to open /dev/nvme0n1p1

Unable to read the contents of this file system!
Because of this some operations may be unavailable.
The cause might be a missing software package.
The following list of software packages is required for ext4 file system support: e2fsprogs v1.41+.

Not two seconds ago, it was showing used space and empty space in the partition, now it can’t read it, without having modified it. Refreshing the device list made this warning disappear. How reliable is Gparted these days?

UPDATE: After repairing the boot partition, NixOS boots.