I'm sure I didn't have the replace button ticked. I recorded the first verse of the song and later, recorded a second verse. I then applied Melodyne through the event manager by right clicking on each clip and choosing "Edit With Melodyne". I shut down everything for the day and the next day I decided I wanted to change the second verse. Everything was in place at the start of the session so I went to the second verse and deleted all the clips and redid the entire second verse and applied Melodyne the same way to the second verse as I did to the first and original second. I just took for granted the first verse didn't change but upon looking at the beginning of the project I found that all the clips were scattered and out of place as if the clips were displaced. I cannot show the screenshots because I corrected them by re recording them. Today I started a third verse and when I last checked everything was still in place there.
One clue though: When I originally recorded the first verse I applied Melodyne via the old transfer method but I decided I wanted to use the ARA Integration method so I removed Melodyne from the track entirely, saved the session without the Melodyne and went back in and re applied Melodyne via ARA. I then saw that a folder named "Melodyne" was on my desktop and I like to keep things together in the same project folder so I moved the Melodyne folder from the desktop to the folder of the project I'm working on. I hope this helps you to help me. I'd like to know what's going on.

JB