No memory cache has been configured

I didn’t want to necro the old thread, where the suggested solution was checking the suggested configuration (which displays another error message) or checking disabled_functions.

OPcache is up and running according to phpinfo, and it seems to cache nextcloud scripts:

1,171 files cached
Script
/www/nextcloud/lib/private/TempManager.php
hits: 476, memory: 18.95KB, last used: Thu Aug 6 19:56:02 2020, force file invalidation

/www/nextcloud/apps/systemtags/composer/autoload.php
hits: 476, memory: 784.00b, last used: Thu Aug 6 19:56:02 2020, force file invalidation

...
etc

Any ideas on why Nextcloud says it’s not configured?

I’m running 19.0.1 on a fresh install of Debian Buster.

$ grep ^opcache /etc/php/7.3/apache2/php.ini
opcache.enable=1
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=10000
opcache.memory_consumption=128
opcache.save_comments=1
opcache.revalidate_freq=1