Something a little tricky I just noticed: If using independent playback of voices in a staff that has a slash voice as well, the names won’t necessarily match between play mode and write mode. I think it has something to do with the order in which you created the voices. I’ve got a situation where I’m using the different voices to play different articulations in VSL (I love that I can do this now!), except I have an instrument with 2 slash voices, and so now what’s called down-stem voice 1 in write mode is called down-stem voice 3 in play mode. All other voices are similarly mixed up.
Yes, we don’t differentiate between non-slash and slash voices in Play mode, so that will throw the numbering off. Unfortunately there’s really no fixed name or number for any voice on any staff in Dorico, which is wonderfully flexible, but does make it tricky to draw a strong connection between them in Write and Play modes, especially when the Play mode UI also tries to draw a connection between voices in different flows, which have completely different internal identifiers.