Yeah, that's normal. Once you follow the rest of the root instructions, it will say n/a in the corner. It's because you unlocked the bootloader.
Sounds like you didn't flash the dm no verity or magisk. Also, it will continue to boot to twrp until you do the following
This version of TWRP is not reading and clearing the bootloader control block (BCB). So, if you do a factory reset via Settings->Backup & Reset->Factory Data Reset, you'll be stuck in a TWRP bootloop.
The quick workaround is to reboot to bootloader, then proceed from there to Start. However, you'll need to do this *every* time until the BCB is cleared.
To clear the BCB manually, issue this command in TWRP terminal:
Code:
dd if=/dev/zero of=/dev/block/bootdevice/by-name/misc bs=1M