Have had conversations with jBridge developer Joao Fernandes...a great guy by the way.

This issue can be resolved by accessing the jBridge app and setting jBridge up to run in "separated GUI mode" option. Then restart Realband and then go back into the SampleTank VSTi. There will be a pop-up that says you are running in a separate GUI mode for SampleTank 4. Check the box in this notice to have SampleTank "always on top".

SampleTank will then run as a stand alone app outside of RealBand and you will have access to the "Learn" function in SampleTank 4. RealBand can then control the Volume and Pan of SampleTank 4.

Win10, Intel i7 7700K 4.2Ghz, 32Gb RAM, 2x1Tb HD, 500Gb NVMe, BIAB/RB current 2020 builds, MOTU 828MK3 audio, MOTU Midi Express, Yamaha DX7II, TX802, Motif XS Rack, Roland Fantom XR Rack, Oberheim Matrix 1000, VoiceLive Touch, Kontakt 5.8, SampleTank 4.09