In the urtext edition (page 84 of the pdf) that I found on IMSLP it looks as if the first period is repeated and then... the rest of the piece, without that first period, is played twice? That doesn't feel quite right. And what's this weird mirrored repeat sign at the end? I've made partial screenshots of the beginning and the end. There are no repeat signs in between.
In a more modern edition each period is repeated twice and that's how everybody seems to play it. How does one get from the first version to the second one? Convention? A later improvement that's actually not consistent with the original print? Or some notational nuance that I don't get? And what's up with the weird repeat sign at the end of the urtext edition?