I use WhatsApp on my Huawei P9. At home it works fine, WiFi is via Fritzbox.

At work WhatsApp intermittently has problems. It won't send or receive messages on WiFi unless WiFi is turned off and on every half hour or so. Facebook, Chrome, everything else works fine while WhatsApp isn't sending or receiving messages.

Sometimes, when I try to send a message the little symbol that looks like a clock that mean "we'll send when we get a network connection" shows up. If I turn off WiFi on my phone then turn it on again, it works. If I move to 4G, it works again. Everything else on the phone works fine.

Any ideas? WhatsApp has no settings.

I have the P9 set to allow notifications and to leave WhatsApp running after the screen turns off.