Help for melody in drum section

Hi guys!
Newby here! I have a po 33rd that i bought before some days back. I think this boxer is very capable but i need your help to coaching!
So this is my problem. I have recorded a sample in melodic section and i copied it in the drum section. I trimmed to the sound i want them, till now all good. Now is the problem, when i try to record a new live melody (i press play and then press and hold the write + press sequence 14, 14, 12, 15, 16) the melody that created is different than the melody i play before record it.
What i do wrong, is there any way to write the melody i want?