Sometimes, using both Ethernet and WiFi on the same device can cause conflicts. Try disabling WiFi on your PC if you’re using Ethernet, or vice versa, to see if one connection type is more stable than the other.
Device Manager > Network Adapters, right-click on the Ethernet adapter, and select Properties. Under the Power Management tab, uncheck the option that allows the computer to turn off the device to save power.
You could connect your old router to the Hitron and use it as an access point.
This would help determine if the issue is with the Hitron's routing or its modem function.