After I have synced two songs and they are still loaded but no longer playing and no sync light it will not let you use the ‘Restore’ function in the pulldown to get back to the original BPM. You can double or half the new value but not restore the original. You have to reload the song to get back the original BPM.
I should have realized that. Thanks!
Thank you Phillippe Perras for your help.
The restore button is only for restore the bpm if you change the value. For restore the bpm after a sync double click on the little dot on the right of the pitch fader.