Yeah, it was a combination of an untrusted repo folder and Windows security that collided with stuff. Weirdly, at the beginning, I went to the properties of the whole folder, and it was set at read-only, and every time I changed it back, it auto-enabled it again... But now, after deleting the whole repo folder and placing a new one, everything seems to be running smoothly. And also thanks for the heads up on the meaning of checked-in, otherwise I most likely would have fixed the problem, but still would have believed that everything is still locked