[Description] When a District belonging to my City and a District belonging to enemy make contact with one another in quite rare occasion, Combat Bonus from Fortification does not apply to the Units fighting on these two tiles. Here are some screenshots:

Before Siege attack.

During Siege, nothing strange in this screenshot.

This is how Units get bonus from standing behind proper Fortification. Other Units work without glitches.

However in this case, Fortification bonus is removed for no reason. I suppose it has something to do with "connected Districts"

[Steps to Produce] Reproduce similar environment like the screenshots above.

[Reproducibility] 5/5. It seems that the combat system processes/calculates this action, as if these two Units were inside the Walls of the same City.

[Expected Behaviour] "connected Districts" should not happen at all. Respectively they belong to different Cities, Territories, and controllers. When erecting a fence/wall/fortification, it would probably have been built along the border between two Civilization. And any Gateway on the fence/wall/fortification would be shut down and well guarded at the time of war. Therefore I expect Units like the Draftees in the screenshot should retain +6 Combat Strength bonus from Fortification.