Screen Flickering When Charging - Grounding Issue?

Hi there,

I've repaired a Samsung Galaxy S7 with a replacement screen (the old one was smashed and completely dead.) The replacement screen came with the frame and a new charging port assembly.

The phone seems to be working great after the screen replacement. However, when charging the phone, the screen slightly flickers. This only occurs when the phone is being held by the metal sides - if it's in a case (e.g. the metal sides are not being directly touched), there is no issue.

This sounds like a grounding issue to me. The charging port assembly cannot be easily removed by the looks of it, as it seems to be attached under the screen. I've also tried another cable and charger, which presents the same issue.

Is there any other likely cause of this grounding issue? If anyone could provide any pointers I would be very grateful.

Thanks for your help!

Ben :)