I forgot to mention that I use a Wi-Fi analyser to check that I don't have a channel clash.

As ReneT notes 2.4 is very crowded, to the extent that a completely free channel is usually impossible to find. 5G is much clearer. My router is set to channel 46 purely because it was not the band my home Wi-Fi uses. So far I've never had a clash.

I was not aware the 5G was shorter range! As I'm always within 5m of the router this has not been an issue. How far away can you go before the signal starts to falter on 5G?