Removing and setting back a subwiki owner removes the wiki membership

STEPS TO REPRODUCE

1. Login as Admin
2. Create a subwiki (I have tested with "Only global users are available in the wiki" and "Both global and local users are available" in the wiki scopes)
3. Edit the subwiki's descriptor from WikiManager page
4. Remove the owner (in this case Admin)
5. Click 'Save'
6. Put back the previous owner (e.g. Admin)
7. Click 'Save & View'
8. Observe the Actions column from WikiManager page

EXPECTED RESULTS

Admin is still member of the respective subwiki. The available actions are 'Edit' and 'Delete'.

ACTUAL RESULTS

Admin appears to have lost his membership on the subwiki. The available actions are 'Join', 'Edit' and 'Delete'.

Another thing to be mentioned is that the Administrator is listed twice in the picker on descriptor page (reproduced the issue by selecting the second one).