Sometimes, a Dynamic Preview on your ad set or ad level will show an error that mention ambiguous ad sets or ambiguous column values.
This can mean only one thing: your ad set settings are not in line with your feed. You have to adjust one or the other.
What is going on?
You defined your ad sets per certain columns.
And, you probably also connected other columns from your catalog as "use values from feed" for your ad set setup.
This works fine only in two cases:
if the same columns that defined the ad set are connected from the feed in the further setup
if different columns are connected from the feed in the further setup, BUT they must be the same for all ads inside one ad set.
For the example on the images above, this means that:
you can "use from feed" location_name freely for any parameter in the ad set setup
since the user connected Coordinaten and Radius columns (which are not defining the ad set), this is fine as long as each ad that belongs to one ad set has the same Coordinaten and Radius values.
Where is the ambiguity and what can be done?
First, remember that each row in your feed equals one ad.
You cannot have one ad set with two different ads with different locations, or custom audiences, or anything else that is a parameter of the ad set.
Whatever you defined at this point makes no sense and cannot be resolved.
So, once you located the ads with the value difference inside the same ad set, you have to decide:
Should there be two ad sets for these two ads? In this case just add that column to the ad set definition, too.
Do you want these ads to belong to one ad set? If yes, then these values must be the same.