when setting memory points('cue', then 'memory') in rekordbox i press the 'cue' but on some tracks the cue moves slightly left or right and misses the beat.why?

should i use hot cues instead? previously i used the cdj to set memory points and this was massively more easy than doing it on rekordbox, but for some reason all the memory points vanished.. hence me now setting them on rekordbox first.