Leningrad Evacuating Factories while isolated?

[karmad]

vs AI

Turn 8 I go around Ilmen (yea I know it's gamey vs AI) and cut off the rail line at Volkhov. The factories remain in Leningrad after turn 8. I load up as Soviets and confirm I can't rail them out. I don't reach Sviritsa, but bomb the port during turns 8 and 9. I do 53 damage by turn 9, and in turn 10 the units around Leningrad are either out of supply or are in beachhead supply but now they can also rail out the factories in Leningrad? Damage at Sviritsa stands as 51 now. Possible bug in allowing factories to be evacuated if city is in beachhead supply? Also note when attempting to rail factories INTO Leningrad area, it gives me the option to rail into the area with the green hexes, but nothing happens when selecting the hex.