filippo209 wrote:
Yes you are right, using the font you indicated it types ok. same for microsoft Himalaya. Cambria, for example, does not work.
Times and Cambria, along with just about all fonts that come with MacOS, have no Tibetan in them and cannot display it at all. When you input Tibetan characters, an app is supposed to automatically use KaiLasa or Kokonor to display your text. This will be the case even if the font window of the app does not change and still says Times or Helvetica or some other Latin font.
When you see unstacked Tibetan, my guess is that the app is by mistake using a Chinese font. Some of these do have Tibetan in them, but only the basic unicode glyphs and not the extra stuff needed for stacking. I think Big Sur has a bug that defaults to one of these Chinese fonts for Tibetan instead of Kailasa or Kokonor, so that the user must then reset the font. This should not be necessary, and Apple should fix it.
It might be worth trying to deactivate the Chinese fonts, but new security features in Big Sur make that impossible I think.