Currently in campaign, mid-1809, and playing as Napoleon with AI on Hard with detection and activation bonuses. Was able to gather the French and Dutch Fleets together and have them led by the Dutch Admirals and they proceeded to bushwack the British fleet down to a nub.
So I had Napoleon invade England. Why not. It was dicey at first since the AI outnumbered me at first with very good generals (Wellington, Salaberry, etc.) After a bloodbath (>200k casualties in total) I prevailed and took London. British morale went to 0 and with their capital captured (and no new capital designated), the Brits should have surrendered. Game over.
But Nope. They started getting +10 NM per turn, but not from War Resilience/Return to Neutral. I loaded as the Brits and checked. They're getting 10 NM per turn for "Options and Events". What "Options and Events"? The log showed nothing. Taking over the Brits I see nothing in the RGD that effect NM except for raids on depots and there were none done. I think I saw the same thing in WoS playing Sweden in the Great Northern War. I took Moscow etc. and every objective except for a couple of minor ones in the far east and the Russian morale kept climbing, eventually eclipsing mine due to war weariness. There just wasn't enough (any really) Russian forces to knock their morale down.
In WoN Wellington fled to Portugal and has a decent sized army, but Lannes and his boys have got him cornered so I can knock him down some, but still not enough to overcome a 10NM gain every turn.
One other thing. The AI players all have huge EP balances. The Austrians have a bunch of reforms available that will greatly improve their army, but he's not spending them. I know there's no hope of getting it fixed, but maybe in the next iteration of the engine they can look at that.