Problem solved!
Who knows that there are different types of quote tags.
I use this typ (copy & past from example
Sound “…\subFolder\soundFile.ogg”
and these are the right ones
Sound “…\subFolder\soundFile.ogg”
Have you been in A-G mode at all this flight? Possibly cursor slews exist?
If it happens again, try switch to A-G mode, and see if CZ is highlighted on the FCR page. If it is, press it to zero cursor slews (it will de-highlight).