Should probably check the name of the parameter in campaign vs that in the target. If they match with case sensitivity, also check if the data being filtered in target is case sesnsitive or not. I would recommend validating below details-
- Target location
- Parameter name matchinng on campaign and target
- Data filtering on target(validate the data in campaign with the filtering, specifically case sensitivity).
If everything seems ok, then I would suggest to create a campaign suppirt ticket. Thanks!