Where did you get the screen, the touch panels on the copy oled, HO3 and LCD versions of the iphone X are the cheaper kind (you can see the easy digitizer in sunlight) are not very good.
There was a known issue with the iphone X causing touch problems after repair and this IIRC was a software update.
Try reseating the connectors and see if there is any bits of crud in the connectors on the motherboard.
it could very well be just a bad screen