@OriginalBigBri That's the one, you used to be able to set the main down to WPA2-Personal but they stopped it way back 18months ago at the concept of Comp mode, so i upped and left at that point, WPA3-Transitional just does not play nice with some devices and that is the setting on the Main WiFi. Really and i know it's a huge pain, but the BT Smart Hub 2 just same as the PN2 version with a working ATA port for the DV Digital Voice is were and would be WAY BETTER for your dad's home network, if me i would be straight onto EE and trying to get them to send one, do appreciate the time/distance problems you have. Just shout or PM if you need.
Make sure you do have an Ethernet device with you, if not you will have to wireless web manager from your device and that should work no issues browser wise, https://192.168.1.254 and also check make sure your teamviewer is FULLY functional so you can remote at anytime to the Hub/devices.
Find the spec of the HP and if it is a wifi 5 device onwards turn the 5Ghz on in Comp mode, off by default. If it won't connect then highly suggest you go down the BT Smart Hub 2 route.
