After changing a soft synth's patch via its GUI, the information will not be updated in the Track window.
After changing patches in the above way and closing down the soft synth's window, the "OK" button of the "Track - Qtractor" dialogue box will be greyed out, meaning that you need to close it either with the Cancel button, or the dialogue's top left/top right buttons. Although the patch itself does change correctly, the information in Track/Track's "Bank" and "Program" will not update.
Following a change in the soft synth's GUI, the Track's "OK" button should be active and its "Bank" and "Program" information should be updated.
Changing the Track's "Bank" and "Program" directly (i.e. rather than through the soft synth's GUI) works correctly. The OK button is enabled and the information is updated.
*As discussed here: