Your phone clearly isn’t working as expected.
Given the ‘screen noise’ you do not say if you have checked the screen is attached properly.
It could have worked well when leaving repairs and the transportation has disloged the screens connectors.
So have you checked all the screws? Lossen them and then tighten them carefully.
That doesn’t fit with the topic you linked too, maybe you only read the first post etc.
Please read that topic more thoroughly for example the one below and a few more.
See also similar topics ~ here’s another
Search for example:
https://forum.fairphone.com/search?q=screen%20pixelated
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