2 Questions - WLAN connection and DAB interference when charging phone

Two questions, sort of related.

I'm having "fun" getting a reliable WLAN connection through my phone. I'll have my hotspot on, and in settings confirm the phone is connected, but I only sometimes get the white world with WLAN illuminated and then the subsequent traffic flow info in my sat nav.

I have the phone connected to the USB port. But, if I have it unplugged from the USB it is much more reliable a connection. However this mean the phone isn't being charged, so if I then plug the phone into a generic 12v socket in the cigar plug (doesn't matter if it's either the front or back one) the DAB signal is blocked.

I hope that makes sense.