Instruments available in different flows

I have set up players with doublings in flow 1 of a piece. However, flows 2 and 3 do not seem to have those instruments available (they do not appear in Galley View). How can I fix this? there is clearly something I am not understanding. All the flows were imported from other files.

In Setup mode, select the Flow, then tick the Players that you want to add.

If you want to all all the Players to a Flow, it’s quicker to select all the Players, and then tick the Flows that you want to add them to!

Imported flows only have the instruments in that file.

Thanks benwiggy! I think the imports confused things, so I just started again. All is well now.