VNAV - adding crossing restriction distances on STARs with transitions

[Chaz]

When going direct any waypoint that is the beginning of a transition on a STAR, and adding a crossing restriction distance BEFORE the waypoint i.e. KIIDD/-20, the FMS does not accept it and results in an error ALONG TRK WPT N/A.   However if I type KIIDD/+20, it will accept it.    I tested this at several airports (ABQ, ELP, OKC) with STARs and it occurred at all of them.

But it works at waypoints/VORs when a STAR is NOT loaded in the FMS.  I could fly direct KIIDD, stand alone, and cross -20 east  or west (+20) if it was just KIIDD in the FMS and no STAR loaded.  Looks like the FMS coding doesn't like a crossing point BEFORE a waypoint that is the beginning of a transition.    Every waypoint after the first waypoint works fine +/-.  

Edited May 12, 2022 by Chaz