Error: Failed to grant permission of database ccnet-db

Error: Failed to grant permission of database ccnet-db: You are not allowed to create a user with GRANT

This happened as I am installing Seafile 8.0.7 from the tar file on Lubuntu 20.04.3.
I have been running the script setup-seafile-mysql.sh, and got to the point where it displayed my configuration data. I wonder if the script had not connected to mysql as root but as the non-root user that I created, seafile.

I expect to be able to connect to mysql and grant the necessary permissions to that user as described in the documentation, but the script may need attention to make it easier for people to install.