u/Still-Fix5383

Hey guys, so im wondering how everyone is setting up their turntables? Bc, when I try to mash two songs together, it doesnt seem to stay consistent even tho bpm reads are matched? Im starting to wonder if this is a hardware problem. I have a Numark tt200 that hasnt been serviced, as far as I know. And Ive always been just eyeballing the "height" of the turntables. Do turntable users use an actual level to get it perfectly flat? What exactly am i doing wrong here? Thanks