I make 5 weight Japanese fonts with style names Regular, Medium, SemiBold, Bold, ExtraBold.
OTF fonts exported by Glyphs
When trying to select with Microsoft Word or Adobe Acrobat Pro DC,
The Regular and Bold styles disappear.
Other weights such as Medium are displayed properly.
Because I want to fix the problem
With custom parameters for the instance
I set ID: 4,1,16 in Name Table Entry,
If you export to OTF, the settings will be lost.
The sample on the left hast the “Bold” in name ID 1. That is a very bad idea as then you loose style linking and that means when someone uses this font and presses the “B” button in the Word, it will produce a fake Bold instead of using the actual bold font. The rest of the table seems to be similar enough so that seem to be what that version of Word is showing. But if it only happening in older versions, that was most likely a bug. And never try to fix bugs in some apps with introducing bugs in your font.