Thanks. There is this-
https://tracker.moodle.org/browse/MDL-37153
and also a related one.
https://tracker.moodle.org/browse/MDL-37153
This is the same issue I think but one is closed for some reason and the other is considered minor, as there's a work around. However I can't get the workaround to work either.
Rapidly losing faith in Moodle here.