Hi, i use windows 10.

Let's start with my disclamer: This solution may not work on all, but worked for me. And maybe you lose your progress, i do not know.

I installed Township with microsoft store, made new game in township and could connect to facebook.
Somehow i managed to remove it, but never able to connect again.

I search and search but i find no answer, and the basic official help did not help either.
I uninstalled Township, and installed it again.

Now i could connect to Facebook and my city was still same level, did not lose anything.

Hope this is help for someone