Internet radio cuts out

[Daz2024]

I've connected my Yamaha receiver up to my Three 5g router on the 2.4ghz frequency and it keeps cutting out every few minutes.

When I revert to my virgin router it's fine 

Any suggestions for a fix before I send it back ?

[Daz2024]

Now lost WiFi altogether,rebooted and 2.4ghz has come back but no 5ghz.

What a piece of junk