mysql_upgrade from mysql 5.7 to MariaDB 10.3.12 fails for "sys" schema

Upgrading from MySQL 5.7 to MariaDB 10.3.12 gives a lot of sys schema related errors as attached.

Process:
1. Remove MySQL 5.7 binaries (rpm -qa | grep mysql | xargs rpm -e)
2. Install MariaDB (yum -y install MariaDB-server)
3. Execute: mysql_upgrade

After the upgrade completes with the error messages, a server restart does not show any error messages, but a re-execution of mysql_upgrade still throws the same error messages.

Just to test, I dropped the sys schema and did a server restart followed by mysql_upgrade and did not get any issues.