It seems that syncing upright mode is not working properly. According to Lightroom – Hilfe | Upright – Automatische Perspektivenkorrektur | Lightroom 5 if you want to sync the mode and reanalyze each picture, you select upright mode and not upright transform when syncing.
However, when I do this I get the same exact result as selecting upright transform. I have played around with the options and I have found no way to produce any different result. It always only applies the same transformation. (I tried this in an exaggerated case where one picture was titled by 45 degrees so the wrong result was obvious). Is this a known bug?
I'm running LR CC (2015) on Windows 8.1.
I have the same problem
LR CC (2015.3), win 10