Small Misfire m42 bmw turbo

We had setting the engine until 0.7 pressure. When we try 0.9 we have some small misfire, and I can see a little flames from the external on the hood. Also, on the datalog I see that the dwell on boost is unstable from 2.7-3.3, which I set up to 2.7ms on 13.8V. We use stock spark plug from this engine m42b18. Is this the reason for misfire, or it is possible a overheat coil or something other?

Any opinion on that ?

Often "Dwell scatter" is an indication you have a trigger problem. I would start by investigating the trigger waveform first, make sure polarity is correct etc.