We have the same issue.
We are running OJS v3.3.0-3 on a Debian v10.8 system, running Apache v2.4, MariaDB v1.10, and PHP 7.3 (FPM).
The user who gets the error message is a journal manager.
Our roles are the default ones:
As the site administrator, I can schedule submissions for publication, but the journal manager cannot.
Any ideas?