GL-X3000 constant reboot after firmware update

I wasn’t able to use Tmobile cellular internet, so i decided to update the firmware to the latest version.
Power down, keep reset pressed, watch power LED turn on, then INTERNET blink 5 times, then 2.4GHz LED become steady.
Use and upload firmware from GL.iNet download center
I tried ALL of them.
Except for the original 4.3.0, all other firmware kept rebooting the router constantly.
During reboot process, power LEd will come on, then 2.4Ghz LED blink twice and then both 2.4GHz and 5GHz LED will lit up, followed by a reboot. This goes on infinitely.
The original 4.3.0 firmware does bootup but says there is a bug in the firmware and i need to update. It then installs the latest firmware and the router keeps rebooting infinitely. So this didn’t work.
Now i am stuck with 4.3.0 firmware and unable to use Tmobile cellular internet.

Is there any other way out?