Hey @rogueDesign,
the problem with your meta query is that for every new member the ad_image key exists in the database. So your EXISTS comparison is always true.
Change your meta query to the following:
I’m using the __return_empty_string helper function from WordPress for the comparison as just leaving the field empty does not work.
For copying purposes: {echo:__return_empty_string}
Let me know if that helps.
Best,
André