I'm having OnePlus 2 with latest OxygenOS 3.0 Beta. I live in UAE. Recently I started getting exclamation mark with connection icon, whether using mobile data or Wi-Fi. I suspected of issue with beta version. But when I went outside the country, I didn't face the same issue. When I came back I started getting the same issue again. This leads me to suspect it's a carrier related issue, not an issue with beta OS.
I tried resolution mentioned in below post already. They are not helpful. Exclamation Point Icon on the Cellular Data Icon + Impaired Data Connectivity - Nexus 5 on Android 5.11
Apparently my OnePlus 2 is not detecting internet connectivity, but allowing me to browse sites and use every services, which require internet connectivity. Could it be that OxygenOS using ping method to any particular server, which is somehow blocked by service provider? If that's the case is it possible to change this?