wavelength being erased while recording

Version: 2.1.2
.exe installer

I have only recently started using audacity. a few days ago, I was recording multiple tracks, but after completing the last one i noticed that the previous six wavelengths were showing up only as a flat line. At this point i had not edited the audio, only recorded it. I later re-recorded the tracks in separate windows, which took a lot longer. any way to prevent this in future?

When you say you were recording multiple tracks, was this one mono or stereo track at a time? Do you have a recording device that records more than two channels?

Does Help > Show Log… show errors, if so what do they say?

Were you recording into an already saved project when you recorded into the same and then different project windows? If yes, what is the path (file location) of those projects? If no, can you look at Edit > Preferences…, Directories section and tell us where the Audacity temporary directory is.

There isn’t any reason I can think of why, other things being equal, recording into the same project would flatline but recording into new projects would not.