Unknown Army & enemy B's army doesn't defend enemy A's province

I have no idea what connects these bugs which just appeared after the most recent update, so here's precisely what happened:

- I noticed my tank army is sitting in enemy A's province where enemy B has an army stationed. But for some reason my army isn't fighting enemy B to capture the province, but just waiting (as if enemy B were a neutral unit)

- Then I noticed the province has an airport. Enemy A had planes and I sabotaged his further-back airport, knowing his planes would be forced to refuel on the forward one - the one my tanks were sitting on. So, I waited for enemy planes to land, assuming that when I attack them, the fight with enemy B will also trigger. But then, the planes just turned into an unknown army upon landing (despite being literally on top of my tanks) and its status was "Waiting: 4min". I commanded tanks to attack this unknown army (thinking it was the planes), and when I did that, the army disappeared. 1 hour later, while my tanks were still engaging enemy B in the province, the enemy's planes appeared again - operating from their original airport! This means they either teleported away from being grounded & pinned down by my tanks, or they never got grounded by me in the 1st place, and the whole thing was an illusion.

- Then my ally's ships spotted an unknown army, even though it was within their inner sight. This would usually mean it's a submarine (and it isn't in the destroyers' inner sight yet, it's only in that of the cruisers, which can't detect subs). But when I patrolled my naval bombers (same level as the destroyers) over it, it's still an unknown army. I can't come up with an explanation.

Update: the army was 4 submarines of equal level to my ally's destroyers and my own navy bombers.

I hope this gives someone a clue... and thank you Bytro developers for working on this game!