Phone coverage poor at home

CiniO

I'm with Meteor, as that's the only network providing reasonable coverage in area i live, work and spend most of my time.
Most of the area is covered with 4g, which is brilliant.

However I don't get 4g inside my house, and even worse, 3g is very poor inside my house (1 to 2 ASU). 2g works brilliant though (10 to 20 ASU)

Unfortunately, my phone (Vodafone smart ultra 6) when set to receive 4g/3g/2g signal and it chooses 3g automatically when at home, making it very difficult to make/answer calls as voice is often interrupting or network is lost alltogether.

When I switch phone in settings to receive 2g signal only, it works brilliant.

I don't need 3g or 4g access at home, as I have home fibre broadband so phone is on wifi when at home.

Is there any way to force my phone to use 2g when connected to my home wifi and switch automatically to 3g/4g when not at home?

It's just a bit of a nightmare to switch settings from 2g only to 4g/3g/2g everytime i leave my house.

ED E

Two ways I'd look into:
NFC Tags to trigger it at the door No NFC
Using Tasker to set it - Will require root (no way around that).