So, I have now solved the problem of the "held chord" concerning Real Track no playing fingerpicking (as it should) but held chords instead...

Under Song Edit/form/settings, I unchecked "Allow RTs shot, hold & push"
and everything is "back to normal" and nice fingerpicking business.

Checking this option comes back automatically when playing the song new.
So I had to save the version with fingerpicking RT 2553 as well as all other songs containing this RT.
Bernard