Movement calculation broken in China

[Duedman]

Hi all,

in my current match I noticed several times that units were able to cross at 1 AP cost where they never should be able to do this.
In the following link this can be seen.
Additional info: The unit had 3 AP at the start. Made a prepared attack -1, swapped -1 and then could have moved into mountains.

https://youtu.be/uw9bSfoz5ss?si=6CD4HenhfAVcoaGN&t=1949

I consider this a bug and tried not to abuse it.