To confirm this happens and a save. Bascially in early 1862 the US civil war ended in a white peace. The US was clearly winning and the war was active. Also its a 'full war' so shouldn't end early.
I've got massive internet problems so really hard to provide saves. But the wetransfer link gives the turn before and the turn when the white peace occured:
https://we.tl/p8hVoXdbbD