Functionality when playing 'solo'

Dear all,
I have made a nice VASSAL mod for my game prototype.
It works fine when selecting the playing sides in the game.
However, when I select the ‘solo’ mode (for all traits there is Restricted Access allowing for one of the playing sides, plus ‘solo’), some functions are not possible.
Fx I can move both sides pieces around and send them to decks, but I cannot Mask them.
I have tried to move the Mask function above the Restricted Access trait and reverse, but it makes no difference.

Masked pieces (can) appear differently to the owner as opposed to other players. If you want the piece to be masked to the owner, you need to specify Display Style: Plain, and provide a Peek keyboard command (if you provide a Peek menu command as well, the player will be able to peek at the piece from the right-click menu, but that is optional).

Thanks, jrwatts,
I will see what I can do.
Another question along the same lines: somehow movement trails do not appear to an opponent when a piece/card is masked, but only to the owner. This is independently of whether the Mask trait is above or below the Movement Trail trait.
Any ideas?