It is something else nothing to do with double clutching, shifting, or even the Clutch itself. A few other people have run into this issue as well according to the Speed shop near me. With the JB4 set on Map 5 the tune is always learning. So something got screwed up somewhere along the line. One of the fixes is to disconnect the battery for 10 mins, reconnect and that should fix it, if not the suggestion is to call burgertuning and have them re-write some of the code.
09 335i Sport --JB4--DCI--Macht Schnell Catless Downpipes--AMS FMIC--Walbro 455 LPFP--HPF Gen2 Exhaust (modified)