I am at a loss. No, I do not have to do anything special, unexpected, or tricky. I just pick the characters v, macron, and breve from the Glyphs panel. (Well not that v – I typed it – but that really ought not make a difference.)
I disabled Minion 3 from Adobe Fonts and reinstalled it – it keeps on working. Also, as I said above, it already works as advertised with other OpenType fonts. Do check on your side if those other fonts work or not! If they do, it has to do with your Minion 3 (and a bout of font cache cleaning may be in order). If they don't, it has to do with your InDesign.
Something peculiar turned up on my old workhorse CS4, though. As before, after reinstalling Minion 3, I picked the glyphs from the Recently Used part of the panel, and as before it didn't work. However, I noticed the glyphs panel had saved the style as well: Italic, while my test text was in Regular. And hey! After selecting the entire text and changing it to Regular, it suddenly worked (still only with the World Composer enabled). Sorry, scratch that. The character 'a' is still a problem. I think it's because InDesign automatically uses the precomposed "ā" when it encounters a+macron, and then the next step, adding a breve at the top of the macron, fails. Anyway, this was when experimenting with CS4 so it isn't useful for the latest version.
(Apologies for the confusion about the version number. It has been the bane of my life ever since Adobe decided "InDesign 1.0" and "InDesign 2.0" should logically be followed by "InDesign CS", "CS2", etc. – and just when I got the hang of that and repeatedly having to verify with users that they can not be using "InDesign 3" because either it had to be "CS" or "CS3" ... they changed the numbering scheme again.)
... View more