Hello,

It seems that

https://tracker.moodle.org/browse/MDL-66181
https://moodle.org/mod/forum/discuss.php?d=391031

is badly implemented since I didn't find any documentation concerning this change in moodle documentation.

Suddenly making this scope of a change should be better documented in Moodle documentation and also you should inform moodle administratos if this scope of a change is going to happen (one forum post doesn't really cut it).

To get it working again you now have to give coursecreator moodle/role:assign before they can get teacher role on the courses they create.

Also moodle/role:assign is concerned as a XSS-risk, risk of gaining other users information and users can spam other useers.