Click somewhere in the spectrogram south of 4-500 Hz with the Transfer tool.
Then Shift click somewhere north of that point - like at 1,2 or 2 kHz - to get that whole area in between transferred to another layer.
What happens is that frequencies lower than 4-500 Hz - all the way down to 0 Hz - faultly get transferred as well.
If you reverse the order and click the higher frequency first this will not happen, which of course is the correct response.
This is easy to see if you transfer from a green layer to a mauve (typically from Crowd to Vocal).
If you at first click a higher frequency instead of 400 Hz, like 800 Hz, you can see a part of the tranferred zone ’hanging’ down a bit under that chosen frequency.
OK, this is not exactly what happened to me- I did notice some unexpected behaviour, but different than you describe
If I:
transfer tool: click around 300Hz (brush area has transferred to target layer> then shift+click at 1KHz and I get the behaviour as expected (original 300Hz selection and everything inbetween up to highest freg selection)
BUT,
I first followed your instructions incorrectly and did: shift+click on lower freq area (which worked correctly)
BUT
I jumped thru undos to get back the 300Hz selection: then shift+click above at 1KHz and the previously selected area lower than 300Hz area is selected as well, which I would say is unexpected behaviour
right…