Cubasis with GarageBand and FL Studio instruments

SampleTank is great but it doesn’t work with Cubasis ((
I checked it in different ways.
It seems that these two apps conflicting on the background sound level.
That’s why I tried to make Cubasis work with GarageBand and FL Studio.

Same thing with BeatMaker 2 (May be I’m wrong with BM but I couldn’t manage to make it work as instrument for Cubasis)