iPhone 12 mini screen dims very dark when plugged into charger
Hello, I was having a Issue with my iPhone brightness going very dim. I followed some recommendations to turn off auto brightness, turn off true tone but was still having the problem. I have diagnostic done at Apple Store, then I have screen replaced at Apple store then I have everything else replaced at Apple store and I finally realized I am only having this problem when the phone is plugged into the charger ( original 5w or 18w). Which is often since I am constantly running apps and using the gps. It dims to a level that is not ideal. While I can still see, it’s just barley visible and uncomfortable. Is this a known issue?
Problem was reproduced on the brand new iPhone 12 mini at the store.
Apple representatives are not experienced enough to help me resolving the issue.
iPhone 12 mini, iOS 15