Truenas core and nextcloud opening opcache to configure opcache.interned_strings_buffer

How much data is stored there?
How many users?

Plug-ins are unsupported and unmaintained at this point, and shouldn’t be used.

I would recommend installing Nextcloud using

Scripted installation of Nextcloud 29 in iocage jail

and migrating your data over to it. Once that is done, we can go further with your error. That specific error should actually not come up when you use the script, because the script sets that properly by default.

Or you can try SCALE…