Corrupted Audio File after Time stretch

In CB Pro 9.5.1, an audio file I was working on was corrupted after performing a process and then hitting undo.

I sliced an audio file in half and applied a small time stretch on the front (didn’t want the time stretch processing the end of the file)
As expected, there was a slight click after the time stretch at the slice point. I overlapped the two parts and applied a crossfade.

I did not like the result, so I applied undo to all processes. That should have left me with the original un-processed file. Instead the file was shorter and retained a loud glitch where I had created the slice.

I went to the audio pool and re-imported the file - same, glitch and shorter file. So I went to the audio folder inside the project folder, and re-imported from there. That file was not corrupted.

I’ve included an attachment that shows the clean file and the corrupted file. There you can see the corrupted file on top (you’ll see the slice/glitch near the beginning of the file), and the clean original file below.

I remember such a problem before with Cubase - it had to be over 15 years ago, so in the dark ages as digital audio is concerned. This one is a big deal, I do this a lot with vocals, just a little stretch here or there to correct a singer’s timing. It’s got to work right.

Subatomik

Cubase Pro 9.5.1
iMac 27" Late 2015 OS 10.11.6
32 gb ram
UA Apollo Thunderbolt Interface

Same here. It seems that the “unprocessed” version got into the wrong place when hitting undo, like it doesn’t remember its original place.
My workaround is import the same track as a new clip, and continue to work on the new one.