problem with bottle gas cooker

Don't know if this is your problem but we have had batches of oil laden LP gas bottles over the years. It does exactly the same thing and blocks the jets.

You could replace the bottle but remember to clean the inside of the feed hose as well as the jets.

RA.

I believe Rockape is on the money with "dirty LPG" as the probable cause.

This type of gas cooker can also fail by jet blockage from dust, etc.
I replaced my old high pressure gas stove (no regulator, jets control pressure) after a bush trip where bulldust got into the stove, fowling the jets.
I now use a Coleman low pressure stove controlled by a small regulator and besides eliminating jet blockages, I now have infinite control over flame height from full flame to a low simmer on either or both burners.

Just getting back to jet blockages and dirty gas, I experienced a problem with poor gas flame on the stove of our camper trailer. The regulator is mounted below the outlet level from the gas bottle and any presence of dirty gas will cause the crap to gravitate down to the regulator, fouling it. I took the reg to a gas specialist who identified a 50% blockage of the double regulator.
I replaced the regulator and fixed the problem. Another solution to potential dirty gas is to relocate the regulator so that it sits above the outlet level to avoid the gravity problem.