delete submission not working

Someone has uploaded a photo not consistent with the guidelines I have set up.
I've tried to delete it via the 3 dot menu but the photo is still there.
I've done it from both the 3 dot menu of the picture upload as well as the edit option for the whole pollunit.

Not sure what to do next.
thanks

Could you send the admin link and the name of the option which should be deleted to support@pollunit.com. Then we have a look at the issue.