Hi guys,
i had similar problems until the screen failed completly. My probelm was that a connection on the display itself was loose (probably from shaking etc.). I fixed it by removing the display and gently press down the silver coverage which you can see on the image below:
There seems to be a connector from the display underneath, connecting the display input to the small board - that than seems to relay the signal to the mainboard via the connector. My phone runs now fine for the last 7 Days. I also linked the original post here:
https://forum.fairphone.com/t/display-from-fp3-buggy-flickering/62237/47
Hopefully this helps to solve some of the problems with the ghost inputs as well.
cheers
Max