GNOME disks messes up partitions

My disk is partitioned like this:

Every time I run any command (mount, format, delete partition,...), I get this:

The actual disk layout itself is not affected: no problems in GParted or CLI. The problem persist until reboot (logout or lightdm restart does not help).

Tried:

1. reinstalling package
2. reinstalling again with dependencies
3. purging, then installing

All for naught.

Also, the app crashes when partitioning, SMART testing, or making images mid-way. It detects various SMART errors, all of them are false.

I am not dual-booting Windows.