I let the router sit overnight and turned off. When I turned it back on the following day the WAN Subnet Mask was reset to the default 255.255.255.0. The setting can obviously be changed but only...

@Tony I tried using a static IP address but to no avail. But I'm not really sure what I'm doing. What makes the WAN Subnet Mask flip to 255.255.0.0 in the first place? What makes it eventually change...

@Tony The router has been holding its own for the most part & only had to change the LAN IP address once lately. You mentioned changing LAN to 192.168.x.1 with the subnet of 255.255.252.0 worked...

The problem I had was changing the LAN IP address to 192.168.1.1 and getting it stay so that it did not conflict with the modem’s IP address. What frequently happened was the router’s LAN IP address...

Is resetting the LAN IP address when there is a power failure (or perhaps an Internet glitch) a common problem with TP-Link routers? I've had issues with a TL-WDR3500 ever since I started using it...

I left the PC connected to the modem overnight to avoid any problems in case another family member wanted to use the PC. This morning I put the router back into the circuit & got the yellow network...