A friend and I have an identical issue in that pizz playing techniques do not result in any change in playback at all, notes are played back arco. We both got Dorico Elements in the last couple of months, and have since upgraded to Pro, but nothing’s changed (not that this is the reason I paid to upgrade to Pro mind you!).
Seems very simple and I was surprised not to find any trace online of others having this issue. I don’t think it’s the same as the “not playing back when applied on beat 1 of the bar” issue I’ve read about elsewhere. I’ve tried applying the playing technique at many points in a measure and none of them have any effect. I’ve also tried combinations of arco and nat to “reset” the playing technique, and tested the issue in an otherwise blank project.
Upgraded to Dorico Pro today as it happens, so running Pro 3.5.10 I believe.