Tracks not playing at same speed.

Just looked and the box is checked, could it be anything else?

What are you using as a controller?

DDJ-RZ, also having a problem with tracks changing bpm whilst playing when syncd, they're either halfing or doubling?

Did you check the analysis for those tracks? Just load one in the software with the controller disconnected - does the BPM change as the song goes through the grid? If so, then you need to re-analyse the song in the other mode (chances are you analysed it in Dynamic mode but it should be Normal mode).

Which version of rekordbox are you using?

Sorted the changing bpms thanks, but still keep getting a track creeping forward about half a beat then stops, when I bring it back it just creeps forward again?

Also using rekordbox 5

What do you mean by "creeps"?

Like one track moves ahead of the other

Doesn't do it all the time will just randomly start then I restart rekordbox and it stops

Can you get this on a video please?

How do I post a video on here?

YouTube or a file share like Dropbox, Google Drive, WeTransfer...

https://drive.google.com/file/d/1LrPLThlo4z3QIOiuS4pupVhDbdDS8C5T/view?usp=sharing

Again, are either of those tracks possibly analysed in dynamic mode?

Just checked and they're both in normal. The same track doesn't always do it and when I turn Rekordbox off and then on and play the same tracks it stops. 

Where are you seeing how they're analysed? I'd recommend simply re-running the analysis on both of those songs with the preference set to normal and see if you can replicate the problem.