RAX-80 hanging and intermittently slow

Ok, I've had this for a wee while now and although it has good reach it constantly has issues with slow connection speeds which is an intermittent problem and connection issues with the iPad's (Ipad 2020 as well as iPad 3) and the chromebook.  Every so often it hangs on the brand new Windows PC as well and also has issues with my Xbox One and Series X which tells me the issue isn't the devices, it's the modem.

I've changed channels to one that hasn't got anyone else using it which didn't make much difference and this morning I did a factory reset before reinstating my settings.  It's still doing it, my iPad hung before on You Tube and I had a similar problem on the PC as well.  Any other suggestions before I talk to Netgear about my warranty?