Call quality when using wifi calling

[#1]

I don't have indoor reception from any of the mobile networks and have happily used an EE femtocell with Plusnet Mobile and Virgin.  That's going to be switched off soon so  I need to use wifi calling instead.

I've tried wifi calling on a few different phones, including a Mototola G7 and and Pixel 2, and the call quality is quite disappointing, despite being on fibre.  Should there be any difference between 2.4 GHz and 5 GHz wifi? Are there any router settings that I could try changing?

[#2]

You have a more basic problem, PlusNet Mobile doesn't support Wifi calling.

[#3]

I left Plusnet Mobile, then had to leave Virgin last week when they stopped using the EE network.  I'm with 1p Mobile, which fully supports EE wifi calling.

[#4]

In that case its probably worth trying to ensure that the phone is using the 5ghz wifi. The range is less than 2.4ghz but the interference from neighboring networks is usually lower.

Assuming you have a Hub one, then split the wifi bands. Then try the phone connected to each band and see which gives the best results.