Strings play pizzicato with no direction

I am scoring a section for strings attached below. Where the 3 division of the Violas begin to play pizz the rest of the Violas all begin to play pizz as well. This cannot be fixed by placing nat. or arco on these parts. The cello’s and double basses, that are marked arco, also ignore their direction and play pizzcato.
Any ideas??

Welcome to the forum, Jonathan. You need to make use of the independent voice playback features added in Dorico 3. See page 85 following in the Dorico 3 Version History PDF.