Maybe I use too many devices; use my Android phone, my iPad, my Surface Pro and my office desktop. Yet I have never had this problem before. For some reason, when I synch my surface pro, It’s not that it’s not syncing at all because most of the numbers are the same as are the lists of Decs. The only thing that does not match my other devices is that under Due for one of my decks it indicates 0 cards. Curiously, if I add a new card to my that deck via another device and then synch it and the Surface Pro, the NEW card does show up on the SurfacePro version. It must be a setting therefore unique to the SurfacePro. Does that make any sense?
2.1.29 did not sync cards moving into/out of a custom study/filtered deck - this has been fixed in 2.1.30