to reproduce
come from random USB frequency
zoom in and find a marker that is declared with AM modulation
click the marker
The modulation goes AM but does not gets large, even if the UI shows 10kHz (5kHz AF) it keeps USB's default one
click again on AM button, then the audio gets wider
idem for AM → USB
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In the following screenshots the first part is when it's supposed to be in right modulation then transition is when the same modulation button is clicked
USB → AM
(https://i.imgur.com/lbO0zvB.jpeg)
AM → USB
(https://i.imgur.com/Pmy0ViX.jpeg)
Regards
linkz
Will be fixed in the 1.5.4