Songmode inconsistencies with DT A4 and other devices

I have another problem with Digitakt. Master I have A4. From it, MIDI OUT goes to RYTM. From RYTM MIDI THRU to Digitakt MIDI IN. From Digitakt MIDI OUT to Thru Box, which sends me notes to BassStation2 and Monologue. When I press Play in A4 in Song Mode, the Trigs in Digitakt flash, but the notes are not sent. When I press Stop and then Play, everything plays fine. It seems to happen every time I get to the beginning of a song.