Hello John,
A good test might to be to try them out at a friends house first, or possibly if you have access to two cell phones. You could enable a hotspot on one and connect the second cell phone and the switch to the hotspot. If all goes well then the issue could be with your cable modem / router or even the security settings on the device. If you find you are able to connect everything using the hot spot then you may want to troubleshoot the issue with your ISP or consider switching to Eero mesh for your wireless access and turning off the local Wi-Fi on your combo device.