I created a new label track and tried to copy an existing label into it so I could export a piece of the audio and let Audacity create the filename. I kept getting a message “can’t create autosave” or something like that (although I had 40+ GB of free disk), and when I tried to move the focus between label tracks the label tracks changed positions vertically on the screen.
Given you wrote here, you don’t need to write to feedback@ as well.
However, if you want to test in alpha builds, please always test in the absolute latest build, not in one that is five weeks old: http://gaclrecords.org.uk/win-nightly/. I don’t seem to have a problem in the latest build with pasting a label into a new label track.