Good afternoon. It's strange that even through the mobile Internet there is no connection to the network in Instagram and Google Play. And when you checked the connection through the mobile Internet, Wi-Fi on Meizu M5c completely disconnected? It's just that WI-FI connectivity has a higher priority.
The first thing I would do is reset the network in the settings of Android. Where exactly these settings are on your Meizu M5c - I can not tell.
Next, you can connect to another Wi-Fi network, for verification.
Check the date and time settings.
But it seems to me that there is a problem with DNS. It is necessary in the properties of the Wi-Fi network to which you are connected on the phone to register DNS: 126.96.36.199. After that, Google Play, Instagram and other programs that wrote "no network connection" should earn.