CJK fonts are garbled in Android6

OK, checked.
we found "Noto Sans JP" not fully support Japanese.
part of Chinese chars are missing.
look at this:

test font under windows 10, and select Font to "Noto Sans JP"
“注意” display correctly, but "事項" is missing from this font.
and windows using its default font to display "事項".

To clarify: seems Noto font family is splitting occidental, oriental and special char in many files.
The solution would be to merge files belonging from the family in a single entity.

User radaee just explained what's missing from Noto JP font file.
Same issue is when rendering KR, and other oriental characters.

It seems actual solution could be to include DroidSansFallback as reported here www.radaeepdf.com/support/knowledge-base...component&kbartid=25 .