This follows a post from October 2016. It took a few months to figure out, but the bottom line was that I did not do myself any favors by trying to enter the UK from Germany using my American passport rather than using my German Fiktionsbescheinigung, Brexit anxiety notwithstanding.
Ultimately, I had a number of experiences during a few months in Germany after the UK forced me back into German lands and hands at the border. After both joyful and truly miserable, painful experiences, I returned to England. I did the same thing, entering on my US documentation. They gave me 48 hours. My visa expired while I was there.
Once that happened, the fact that Germany had granted me person which was still good for months thanks to International Laws.
I guess what happened was that I’m so attached to being American that I made life more difficult for myself by not doing the obvious and making the most of German permissions every step of the way.
Like most real life events, there’s more to this story than meets the eye, but that is enough to clarify that.