Ah sorry guys forgot that you run ownCloud. As it does not yet support PHP7.3, we install PHP7.2 then and block PHP7.2, which should have happened with v6.23 update.
However if something failed please try to redo the commands I provided above but with replace "7.3" with "7.2".
Having issues with your DietPi installation, or, found a bug? Post it here.