Transition lose some measures before going to the next part of the song

Hi guys,

I´ve been learning and doing some midi-to-BBM work (I got de BB just one month ago) and sometimes when I insert a transition it does not play as I wanted because the transition usually loses some measure(s) and then it goes to the next part. A lot of times I don´t want to lose that measures because they are important. So, does anyone knows how this works?

The same occurs with the drum fills. I guess that the same logic as with the transitions works here, right?

Thanks for your help.