Generate noise removes audio from separate track

When I use generate noise, it sometimes removes audio from the other track I am working with.

I click a spot where I want to generate noise, and I see the top track grow because of the added noise…

…but then I also see the bottom track shrink because the effect removed something from it??? :open_mouth:

video example:

Windows 10 Pro 64-bit 1803

Audacity 2.3.0

Realtek HD Audio driver ver.

Step by step, how are you generating the noise?

I select a position in the audio track that I want to generate noise. Then I generate, say 600ms of noise. I see the noise inserted in the selected track, but in the below track, a portion of the audio near the same timestamp I generated noise for the top track, is removed!

Are you sure that it is removing audio from the other track, and not inserting a space?

Look near the bottom of the “Tracks” menu, and ensure that “Sync-Lock Tracks” is not ticked.