This is baseless and not related to your visit to Madinah. As long as you have performed your Umrah, it is up to you whether you perform another Umrah or not.

If I visit Madinah from Makkah for praying in Masjid an Nabawi and visit the graves of Prophet and his companions and visit the baqi. My parents were telling that we have to perform umrah because we visited Madinah. So, what’s the rulling on performing umrah after returning to Makkah?