We're on Moodle 2.5. There is an account for an external company using our Moodle which gets manually enrolled onto all of their courses; no plugins are used, everything is manually done at the moment. Recently we've experienced problems with the role assignments. The role seems to get randomly unassigned on some courses. The user is still enrolled; just their role gets deleted.
I can't seem to find anything useful in the logs; there is no evidence of changes to the account and none of us on the team can think what might have caused it.
Does anyone have an idea what might be causing it, or suggest how we investigate the problem please?