This issue isn't defining a site. I've had my sites defined and saved for months now. In the screenshot I blacked out the numerical site coordinates so all you hooligans didn't know where I live :)
What happens is that one night I'll connect the mount and it will be perfectly fine. The next night I'll connect and it will say E instead of W. So I'll go in and change it back to W and it will stick for the next few connection cycles, then it will change to E somehow. It happens very randomly.