Yeah, I "know" how it is supposed to work. I "knew" that back then when I bought my first WWVB-receiving clock, too.

And the placement was still fickle.

It's simple to observe:

A) Purchase and install clock. Wait (days). Observe failure to chooch.

B) Move clock. Wait (hours). Observe correct operation.

My world is ultimately bounded by reality, not theory: When it works in one position but not another, then that's the only reality I have to work with.