i know this thread is aging but I’m having the same issue. I’ve tried reinstalling grub to no avail. Ironically, i had a v3 stick laying here and just for kicks ran the installer and it was fine. found the boot drive and booted as normal. I’m not sure what to do aside from ripping hair out. so however the installer was set up for the centOS version it seems to be fine. but no dice for the opensuse version. seems like every time i want to really try this NAS something like this happens and I wind up giving up on it. I’m looking for a reason to leave truenas for various reasons but it’s the only thing that seems to be stable for me. I may wind up throwing unraid on it just to try it out. maybe a future release will have this issue ironed out.