Incoming calls are working with mobile data disabled AND WLAN off - no connection... But Mobile Data doesn't work well.. Maybe wrong config (APN)? Doesn't look like. But internet is default disabled. Why? Why is the internet apn disabled... I think it is a configure / setup / software to hardware error
Or it is just connection (I see a L for LTE or 3G, just things as that if I activate mobile data. But it comes instant (is this normal?). It looks for me like it works but doesn't use it. Like, it doesn't thinks it is internet. Doesn't know how to handle with. IT DOESN'T EVEN TRY TO SEARCH FOR INTERNET. I see that because browser shows instant "no conn..."
Also, the hotspot isn't working 
It is spinning around... around and again around
I HAD TO START RECOVERY FIRST BOOT, ELSE JUST STUCK AT BOOT LOGO. IT LOOKS LIKE TWRP AND STUFF DOESN'T HANDLE WELL WITH DATA PART!!! BECAUSE ANDROID ALSO SHOWED THAT
I HOPE you fix mobile data SOON. I prefer it if not at home, what else should I take??
thank you for the port. FP3, installed Android again with YOUR LINK