Part of one track sound replaced all sounds on other tracks

Hi, I copied and pasted a segment of a mono track to an added mono track, then duplicated it, then made a stereo track.

I then copied and pasted the newly created stereo segment to an existing stereo track. I then tried to re-pitch it up an octave.

Then, something weird has happened. The sound in this segment replaced all other sounds in the corresponding segments in all other tracks.
Strangely, all other tracks are still displaying their own audio waveform, and none of them are muted. Also, audio before and after this segment are still playing correctly their own sounds, but as soon as this segment is replayed, all other sounds just disappear, replaced by the new sound.

Has this happened to anyone else before? What is the cause? Any solutions?

Thank you very much in advance.

I can’t reproduce this on W10 with 3.1.3 or 3.2.0 latest alpha test build, following your steps.


Could you have accidentally engaged Audacity’s new looping function ?

Many thanks for your suggestion. It was not caused by looping but by accidentally pasting a segment of sound to all the tracks via using selection moving down through different tracks. As those selected tracks were not highlighted, I thought the pasting would affect only the destination track intended. Also, because different tracks had different height, making their identical waveform appeared very different, I did not realise this until I incidentally found they were the same today.

You are right, as it was not as it seemed. See my reply to Trebor above. Thank you for looking into that.