Sky fibre when using a network switch the wifi goes down

[tim+o]

So just moved from BT fibre to sky fibre. Plugged the router in and worked great on the items connected via ethernet and netgear network switch. However no wifi. Unplug the network switch and wifi works great - nut onviously thise devuces connected via ethernet don't work. Any ideas? Is it a setting in the router?

[jamesn123]

@tim+o 

What type of switch is it? Exactly what devices are connected via this switch?