Select the “Envelope Tool” (see: https://manual.audacityteam.org/man/envelope_tool.html)
Do your audio tracks have lots of random white dots (envelope points) on them?
If so, see this post: https://forum.audacityteam.org/t/how-to-solve-envelope-tool-problem-solved/62655/2
For illustration, here is an extreme example of the “white dot” problem: