I'm not sure why there is two default gateways showing up for your DNS server, there should only be one normally.
Have you tried to designate the DNS server in the routers set up page?
Using Google DNS usually works well, 18.104.22.168 and 22.214.171.124.
If the connection is still dropping out try using a different wireless channel, there could be channel overlap in your area which can cause this problem. Best to find a clear channel using the Xirrus wifi channel scanner, "link below". Wi-Fi Inspector | Xirrus