Just like the title reads, don't use external storage on nextcloud unless you want to get fucked.
Only use local storage on nextcloud, trying to use the external storage app with nfs shares is a nightmare.
I ended up having a power outage and when the power came back asscloud was pissed. The decryption keys wouldn't decrypt the data on the external share. When I tried to manually do so via the command "nexcloud:occ decrypt:all" etc it corrupted all of my data.