How can I fix some apps not working with WiFi and others do?

[Android Central Question]

My carrier is T-Mobile. All apps on my phone work with wifi except for Snapchat and Instagram. I've tried unplugging and plugging the router but it only worked for a few seconds. I know the problem isn't with my wifi because it works fine on other apps and on other devices. Ive tried turning off fast 4g LTE. I've also tried turning on airplane mode. I reset my phone, and uninstalled and reinstalled so many times. Does someone know how to fix this?

 

[B. Diddy]

Welcome to Android Central! Do those apps work on other wi-fi networks?

See what happens if you log into the router's settings (via the computer browser -- see the router manual to learn how) and disable IPv6.