After upgrading 4.2 -> 4.3  quiz grade items hidden of some courses.
Newly created courses is ok.

I tried dirty hack by directly update records from db:
update mdl_grade_items set hidden=0 where itemmodule='quiz';
update mdl_grade_items_history set hidden=0 where itemmodule='quiz';
then it restored but after some times it hidden again (assume by some cron jobs).

In Gradebook it can't be edited.