In that case my first port of call would be to SCC & check with them as it could be the map having a few issues?Im running a stage 2 map done by scc in st Albans
The main thing a remap will do to increase power is to increase the boost levels - amongst other things obviously. If the boost is coming in too hard or going too high it could be causing issues with the OP's car. Modern cars have lots of safety systems designed to protect the car & especially with higher boost if the car's ECU thinks the car is over boosting it will start cutting things back to protect itself. There could be a mechanical issue with something worn that would normally be able to handle higher boost levels like a damaged wastegate etc but I would still be double checking the map with SCC first.how can a map change fom the way it was programmed to work??