Entering multiple tom notes using ‘y’ key gives a higher pitch on the first, and a lower pitch on the second and thereafter. It even does it in this situation, where when it goes across the barline to the second half note it gives the lower pitch. Why?
AI has been helpful looking at this situation, explaining everything around trems across barlines in Dorico, except exactly why this is happening 
Some more experiments, it’s definitely tied to the 2/4->4/4 transition. Staying in the previous 4/4 its fine going into the 2/4, but the return to 4/4 always drops the pitch, for example on successive quarter notes
