Support Units (sapeurs, pontonniers, ambulance,transmission units) are used to suffer combact losses!!!!
Guess, support units should not been envolved in combact actions!
Attempt a sortie special command does not work.
To trigger Sortie a besieged Force must be manualy moved off the besigied structure.
"Fog of War" may be it's not properly working.
In Thames or Danube Scenery, played as French side, I'm able to see Russian Forces deployed hundred of miles deep in enemy controlled territory, (Russia).
I suggest to check reported points.
JastaV