Some glyphs "missing" when exported

Glyphs
1

Hi all!
When I am working in Glyphs, all “Mac Roman” and “Windows 1252” glyphs are added and available,
but when I export the file, I can’t use some symbols. And if I open the exported OTF back in Glyphs to check, those are missing;

Is this a known issue? Am I missing something? Thank you

2

You might have the option “keep glyph names from imported files” on. That means they might be in the font but with a different name.