UK surrender question

[El_Condoro]

The UK had been plummeting towards zero NM and was about to surrender, so I stacked every UK resource with US units. The UK surrendered and all UK resources passed to US control, except London: the US paratroops stationed there surrendered, too! I understand that the London hex needs to pass to German control for the surrender to be effected but from a game mechanics point of view, why did the US unit surrender and not just move outside London?

[Chernobyl]

Wait is this normal for when Italy surrenders also? Any unit in Rome will surrender?

[OldCrowBalthazor]

Wait is this normal for when Italy surrenders also? Any unit in Rome will surrender?

Don't know about Rome but I saw the London deal also.
I was on the losing end and stuffed US troops into Great Britain just before it surrendered due to 0 NM. The US unit in London was 'disappeared'. It was in an MP game too if that helps.

Also note: Don't invade Ireland like the USA did to have space for their Air Armada. UK was teetering at very low NM when I did the invasion. Boom the Brits national morale dropped to 0
and I was like, "wtf you ungrateful friends haha".....

[El_Condoro]

The other thing that took me by surprise was that the UK ports were available to Axis transports even though I had US units in the (land) port hex. My USAAF was guarding some of the resources thinking they wer safe when voila! all these Germans and Italians rocked up through the adjacent port hexes. Very annoying. I assume I needed a naval unit in the (sea) port hexes to keep them in my possession.