I have 4 of these light as a installing on my plaster ceiling but there is 1 of it keep spoiling like 3 - 6 months once whereas the rest for years also won't spoilt, what could be the reason?

LED bulb not supposed to have a choke/ballast. The old ballast may be causing the LED to die early.
With the DB box fully off, pull out the trumpet and remove the choke (the trumpet should be wired directly to the former incoming LINE of choke).

I've tried to pull out the "trumpet", it is a receiving direct supply from DB same as the rest of the 3 LED which has been there for years.

the socket where the bulbs died very fast could be putting out more current than the rest. When there is too much current, of course your bulb cannot tahan lama. You can try putting a high watts bulb so it can take the extra current.

bad contact?
maybe wanna try cleaning the contact or changed the bulb socket.

High current is one of the reasons....
One of mine friend bulb keep GG...
After checking... The electrician says one of the bulb have more power @ current then the rest...
So solution... Add bigger Watt bulb... And brighter too....

Thanks