It seems that cautionary accidentals in a different octave within the same measure depend on the rhythm. The following picture show two identical measures, except that the first B♭ is tied to an 8th and the second is not. This is somehow affecting whether or not the cautionary ♮ shows on the high B♮ on beat 4. The high B♮ on beat one is required to reproduce this bug. I attached a minimal project containing this as well.
Missing Accidental.zip (423 KB)
I can confirm this happens for me too.
I just checked and it exists in both Dorico 2 and 3.
For what it’s worth, this behaviour is deliberate and relates to time signatures with a half-bar like 4/4. If the accidental applies when the half-bar begins, then it won’t be restated, whereas if it hasn’t appeared in the half-bar, it will be restated. Off the top of my head I can’t tell you why this is, but at some point I can dig back through our notes and even examine the code if necessary to provide the reason.
Sorry if I am misunderstanding you, but are you saying that this is the intended behaviour?
Yes, it’s intentional, though, as I say, I’m not certain why.