Preamble: Since Dorico is a Qt application, on macOS it requires both in-app language configuration and macOS Catalina System App-Specific Language Settings to be set to the East-Asian language you want. Otherwise, unexpected font fallback problems may happen.
In this bug report we suppose that both settings are Japanese. If one’s macOS has Japanese language enabled and set as the system-wide primary language, then the macOS Catalina System App-Specific Language Settings may be unnecessary.
Issue: Dorico misuses Chinese version of Hiragino Sans as Japanese UI fallback font.
What Expected: Dorico in Japanese UI (both of the above settings are Japanese) is expected to use “Hiragino Kaku Gothic ProN” (The Japanese version of Hiragino Sans) as the Japanese UI fallback font right behind the default English UI font.
!!! Considering that “Hiragino Kaku Gothic ProN” has less ideograph support than “Hiragino Sans GB”, the ideo fallback sequence should be: “English UI Font → Hiragino Kaku Gothic ProN → Hiragino Sans GB”
Actually: The programmer or the localization worker misused “Hiragino Sans GB” (The Simplified Chinese version of Hiragino Sans) in this case. Some Japanese users are sensitive and feel sick with fonts printed in non-Japanese glyph standards. // In China, vice-versa.
The issue is that Dorico isn’t explicitly specifying a UI font for the Japanese version on macOS, while it is on Windows. But that will be fixed in the next major release (I have already fixed it in our internal builds). Thanks for bringing the issue to my attention, but that’s all that is required to ensure something gets fixed. Once we know about a problem, we will fix it.
Thanks for letting us know that this issue has already been addressed.
I personally prefer the multi-fallback policy I mentioned explicitly in this thread.
However, at least, Shigeta’s concern is completely solved in your internal builds.
Thanks for your efforts.