I have noted some problems regarding tremolos tied across barlines.
In this example I have simply copied a whole note tremolo to different places relative to the bars. Dorico puts an extra slash on the middle one but they play back identically (as 32nds). It should look like the example below:
In this example however the middle one plays back as 16ths. But if I remove the tie across the barline the playback is back to 32nds.