‘Ctrl c’ does not always copy text snippets from labels; however, Right Click > ‘Copy Label text’ always works, as does ‘Ctrl v’. After copy/pasting labels, then using ‘Ctrl c’ to copy label text, the text that is pasted may, instead, be whatever text was previously on the Clipboard, which could easily go unnoticed if that text happens to be similar to what was expected.
After copy/pasting both audio and label tracks together with ‘Ctrl c’ (which works as expected), the proper label-text-copying function of ‘Ctrl c’ is magically restored!
I am working with multiple project windows open, each with several label tracks and many labels. The problem is intermittent and unpredictable, but seems to arise after working with labels for a time; however, I have not been able to consistently reproduce it. The ‘fix’ noted above (copying an audio and label track together) was only just discovered, and I’m hoping that it may provide a clue to the underlying bug.