Iv looked into this issue further and it seems to be a long standing problem - since 2017! The main point of DJ software and hardware is to mix music and Rekordbox seems to have a problem with this fundamental function. This seems absurd in this day and age! If the problem is not resolved i will be going back to Serato.
I started out on vinyl many years ago and mostly play old school funk, disco and boogie, which is not quantised to a beatgrid. I can mix by ear well enough but as anyone who knows will tell you, mixing two tracks together with live drummers is no easy thing. Mixing house and other quantised music is a walk in the park compared... Hence i edit the beatgrids on my old school tracks manually and am then able to mix them seamlessly. That is until i started using Rekordbox, which for me and many others, is currently not able to keep time in loop mode. Given the amount of money these units cost, where is the technical support on this issue?? If Rekordbox want to lose customers this is a great way to do it.