v0.86 FE BETA - unit path/movement issue

issue - I've found recently in late game once many cities are build and I control 1/2+ of the map that my units have severe issues moving around/through cities.  This became very apparent once my units started walking way around a mountain pass to get 1 square the other side of a particular city.  The city blocks passage from one area to another along a thin stretch of land with a mountain range down the center.  I've noticed this else where now too as the movement of units seems to have very similar issues to that seen in EWOM.  I'll send in a save game and you can see yourself.

Thanks