Hi there,
I have had this issue twice already, also after replacement of the screen. So either there’s a whole bunch of touchscreens produced that have the same issue, or there is something going wrong between the main component of the phone and the screen. Whatever the problem is, it seems like a production failure, like @jens.hermes said.
Knowing the problem reoccurs, and that this is pretty frustrating, I asked the zendesk what my options are. From what I read above, the issue is very common and there seems to be understanding from the staff. I will keep you up to date about my ‘ticket request’.
@BeMiGro You were suggesting that having the phone in your pocket might cause the issue. I was thinking the same, so thank you for mentioning it. I think it might be an issue either because of the force on the phone (the phone’s pretty big and might suffer from ‘tight’ pants) or because of humidity (e.g. when I cycle on a summerday humidity increases, and I cycle daily for 1.5 hours). What I’d like to ask to you all: do the people that have the complaint carry their phone in their pocket? My reasoning: as it is usually men wearing their phone in their pockets, this might explain why mainly men are having the issue (just a little hypothesis, based on names I read above).
Anyway, next time my screen or complete phone is repaired / replaced, I’ll try to carry it in another way. If I get the chance, I’ll also keep you up to date about this!
Good luck too all of you that are suffering the same frustrations 
- Boudewijn