I have HDD formatted as ExFat and couldn't mount it some weeks ago. The error was about superblock but no idea how to fix it, repair disk showed same error. I have to use this tool to recover data on the driver eopkg it testdisk
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After reformat as ext4, the driver still on and off when I try to mount/unmount it. But with recent update (linux kernel I guess), it suddenly works again. I could mount/unmout it without issue. Not sure if it's coincident, but just want to share it here if someone has same issue.