It has to be the screens. If it will work on the original screen but not the replacement screens and you have transferred the original home button to the the replacement screens and they are connected correctly then the only problem is the screens you purchased. I would find a higher quality screen and try it. Ifixit sells them.
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=== Update (05/24/2020) ===
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That's a lot of work and might not work and he will lose the warranty on the screen. I have put on quite a few screens on and have only has the issue that I had a defective screen twice. It will happen with electronics. In my opinion he just needs to buy a high quality screen and he should be fine.
It has to be the screens. If it will work on the original screen but not the replacement screens and you have transferred the original home button to the the replacement screens and they are connected correctly then the only problem is the screens you purchased. I would find a higher quality screen and try it. Ifixit sells them.