1844 bug hex J15 is not accessable after laying Furka-Tile

[volker18xxdev]

1844. Scenario: Rhb-Turn. Lay the Furka-Oberalp Option and lay the Tracks. in the current state the Hex J15 to reach the destination Hex is not accessable.
      After laying the Furka-Oberalb-Tracks the Routine for accessable Hex for the RHB should be restarted.

Game https://18xx.games/game/181044?action=370 RHB Tracklaying step.
Undo https://18xx.games/game/181044?action=338 and don't close the Furka-Oberalp.
Goto to step: https://18xx.games/game/181044?action=370, Player Ganymede close the Furka-Oberalp and the RHB want to build a Track on J15. In this case it is not possible.

[philcampeau]

I had to read this one a couple of times to parse it. The issue being reported is that the graph for available hexes isn't updated after the Furka-Oberalp is used, so if it's not already in place at the start of the operating corp's turn and then is used, the hex at the other end of those track tiles is unavailable for tile lays.

I recreated the described scenario from their game here