The oboe and clarinets here have the same trills as flute and piccolo, and they appear in galley and full score views, but NOT in condensed view.
I have tried deleted them and re-entering them, same problem. 
TrillBug.dorico (765.6 KB)
Select everything (with condensing turned off), right click, Voices, Change Voice, Up-Stem Voice 1.
To avoid issues like this in the future, make sure the stem of the little orange note next to the caret is pointing up. If it’s pointing down, press V. When in doubt, always use Up-Stem Voice 1, even when the stems will be pointing down. 
Further reading on voices:
Thank you! This file was imported from music XML, no idea why those voices came in as voice 2!
The link to the manual given above is to the Dorico 2 manual, you can find the relevant task in the Dorico 4 manual here.
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Ooops, apologies.