Opponent is AI.
I should also say the map is modded. Mind you, Gibraltar location has
not been moved. I did make it a fortress and used a custom resource tile for that (sprite #119).
Could this be the cause? How did you implement the blocking of movement? Hard coded hex number? Or am I missing something that I accidentally broke while modding the map?
This is from my mod:
As you can see the tile characteristics are unchanged. The resource I added for Gibraltar is new though. Could that be interfering?
Update:
The plot thickens. Look at this pic:

What you are looking at here is the
virgin 1939 stock scenario in the Editor. Untouched. Not even a png file in the 1939 directory. Nothing. Clicking in the editor on sprite #119 in the Resource tab results in a blank. I used resource sprite #119 for my custom Gibraltar fortification in my mod. Coincedence or is resource tile #119 bugged?
Also the editor freaked out on me many times now when I select tile #119. The editor refuses to close when I click quit. Only closing Warplan in the Windows Task Manager altogether will solve this. So there is definitely something wonky with tile #119 IMHO, and this was not the case before AFAIK.