!Problem looping with my DDJ-SB2 and Djay pro for Windows! Please help

Hi guys, I’m having problems with Djay Pro for Windows when i’m looping, just with my controller (Pioneer DDJ-SB2). What happened, when i hit the auto loop button and then select 2 or 4 or… everything is right until y change the loop log.For example it is looping 4 and then when i go to 2 it sound bad, the sound cuts, and some times it returns to the loop start so bad affecting the mix. I’m new using Djay pro and i hope someone can help me.