only connect to 2.4ghz

Hello,

I just bought a wireless doorbell that connects to my iPhone X’s Max (iOS ver 12.1.2) using my home WiFi which is Sky. Acc to the instructions for the doorbell it will only work properly if my iPhone is connected to 2.4ghz network!

on my Sky Q Router wireless settings I have “synchronise 2.4ghz and 5ghz settings” box ticked.

once I connect the doorbell app to the doorbell I am getting an error message “Fail to bind the push service. Please enable it manually”. The app’s Push mode defaults to Silent, even when manually selecting “Call in”. Essentially this means that though I can access the camera on the doorbell and view/record both still and video footage I do not receive push notifications that someone has pushed the doorbell button or that the PIR detection has been tripped! 

I have tried restarting the Sky Q Router, the iPhone, the doorbell. I have also tried unticking the “synchronise 2.4ghz and 5ghz settings” box. I’ve also sent an email to the manufacturer but not expecting a quick reply due to Christmas & New Year

is there a way to have my iPhone only connect to 2.4ghz?

Any ideas/suggestions would be greatly appreciated