@Tigersb 

Set up the 841N in the same room as the router, and configure a different extended wireless network name so you know what network is what. Another recommendation would be that the 2.4G and 5G name of your main router is different if your router has a 5G network. Finally, verify the wireless network password you are providing the 841N is correct by testing that same password on your smart phone by forgetting the network.