Problem is when I put song from library to running playlist just after the song on air. Although the song then appears in Next, when the air song ends, old scheduled song starts to play on air anyway. Then the mess with songs and next songs continues.. So the result for now is not to put new desired song from library just after song currently playing.
Please take a look at pypo.log to see if the schedule was updated correctly. Or you can simply upload the whole airtime log folder here and let's check it out.