Some apps fail to make internet connection via a specific WiFi

A

AC Question

I've Samsung Galaxy J5. (Some) apps including "Google Play Store" fail to make an internet connection via my Home WiFi Network, whereas other devices does not appear to have the same problem while connecting to the same WiFi. However, if I connect my phone to another WiFi network, all apps work successfully!

To describe more: Google Play Store sometimes gives a blank screen or "Connection timed out" message, while Facebook app feels to make very weak requests most of them fail, however, Messenger works just fine but doesn't easily send photos. YouTube and Chrome also work very good.

Still, it's strange that the problem occurs only at my device. Others connect to my WiFi and use all their apps! I tried to set the router and the device to Google DNS, but still no luck.

I didn't have this issue before upgrading (officially) from lollipop to marshmallow. But still I can't be sure that it's related to marshmallow.