In the settings menu (gear icon), ensure your MIDI controller is mapped.
The B-3X operates in two modes.
The official PDF manual explains what a control does, but not always how to use it musically. Here is the practical guide. ik multimedia hammond b-3x manual
Problem: The Leslie won't speed up/slow down. In the settings menu (gear icon), ensure your
Problem: The sound is too clean.
Problem: Latency issues.