Hi there @richard
The reception for my GSM en WiFi is quite okay. Never really had any problems. Maybe contact the support team directly about this issue.
Further, GPS-fixing has been a bit of struggle. I’ve tried to explain in this post (and maybe GPS does not work) the steps you can take to get it to work.
Lastly, the fact that your screen stays black when making a phone call isn’t quite normal either. I’ve never encountered this problem. You can resolve this by enabling the ability to end a phone call with the power-on/off button. It’s located under Settings > Accessibility.
Please keep us posted about further developments and/or issuess.
Kind regards,
Robin.