Rewind feature

I have just loaded Ms4 in the past week, not happily, but I did. I have hundreds of pieces I've done over the years and now I have to open them one at a time in Musescore4 to get them to start working again.
It is what it is.

My current issue is that the "rewind" button on the panel at the top doesn't seem to work at all.
Whether I just click on the "back arrow" icon or whether I wait for it to display the prompts "rewind" and click on that it has no effect.

Is this an upgrade feature or an issue?