That is “over ignition” which means you have too much gas by the time it finally ignites. This could happen when the gas/or air flow is obstructed. Or if the burners are occasionally not sparking.
Watch the sparks on the problem burners. You should hear all the burners spark simultaneously at a regular pace. Are the problem burners sparking regularly in time with the others? Or are they skipping a few times? If they are missing a spark here and there, gas is still flowing during that time-which results in over-ignition when it finally does spark.
It can also spark in the wrong place,i.e. it can spark down or to the side or underneath. The spark must cross the path of the gas flow in order to ignite. Anything (food, insect, rust) that is obstructing the gas flow can also cause delayed ignition.
Check those things and let me know. Videos or photos might be helpful.