I’ve proven that doing a speed test with the Android app ‘Speedtest’ will cause the internet connection to be blocked, and hotspots stops.
If you don’t do this, hotspot works fine.
It’s just that I run a speedtest on all my mobile services when I first connect, to test for bandwidth, looks like there is something in the StarHub network that does not like this and block the internet connection.
I need to reboot the phone to get internet connection back.
I’ll post these findings on the StarHub forum, as this has cost me about 4 hours in investigation, and I’ve tried 4 SIMs.