I'm pretty sure is FAT32 but it is showing as "Generic Hierarchical” ? Never saw this type of file before, strange lol. Anyway, I must be crazy or something, but I found out something interesting, at least, I tried it 2 times and worked the same. If I turn off my switch pressing the power button and then turning it off completely, and afterwards, after 5secs I turn it back on, If I connect the charger, the boot will start in about 30sec. I don't know if the charger is actually doing anything, I usually just let me switch in sleep mode for the sake of convenience, because of the time it took me. But surprisingly, in those 2 times in a row, I even timed the boot, it actually boot between 30 to 40 secs
Edit: I did it again, and took a screenshot of the timer when it booted