XDJ RX Beat sync problems

Hi, I just recently got my XDJ RX, and it's a great bit of kit. The only problem I'm having is when trying to use the beat sync function, it doesn't always work that well. I used to have a paid of Numark NDX900's, which, although they had a beat counter, it wasn't all that accurate, never mind being able to beat sync, so I can beatmatch no problem, I just thought it would be fun to mess around with the beat sync function.

The problem seems to be that although the tracks have been properly analysed in rekordbox (the beat grid falls on the kick drum exactly), often it won't match up perfectly when I try to use the beat sync function. This is not a problem in itself, as I have just been using the jog wheel to make adjustments to the track I'm mixing in, to get it synced up perfectly. The issue is that it seems to try to correct itself over time, i.e. to sync itself back up with the out of sync pattern it was in before I adjusted it with the jog wheel. I would have thought that beat sync would have meant that it would maintain a steady tempo in comparison to the other track that was playing, regardless of whatever I do with the jog wheel, if that makes sense?

Also, is there any other way of adjusting the tempo than using the slider or the jog wheel? My old decks had a pitch adjust button on them, which you could speed up or slow down the track with, temporarily. I realise this might be a bit of an amateurish type of function, so it probably hasn't been included on this model. I just found it easy to judge how much the track would speed up or slow down, compared to the jog wheel, which can be a little sensitive at times, if you try to speed up a track a fair bit, to get it in sync. I can't see a button that does this, but perhaps there is another button with a dual function.

The main problem is the first thing, the second point was just me ruminating, really.