Wifi function on my Ubee router/modem goes out and a weird ip address appears on my port forwarding

My Ubee router/modem model DVW326B is having WiFi problems. Every once in awhile my WiFi function on my Ubee router/modem goes out except for 2 of my devices that are wired to my Ubee router/modem. After i reset the Ubee router/modem I noticed that this ip address 68.108.115.15 appears on my port forwarding page on my router. I have no idea why this ip address appears their but once I delete it my router/modem wifi function work fine for about a week or 2 until i have to repeat the process again. Is there a solution for this problem.