InDesign seems to struggle to recognise installed fonts - possibly something to do with how Skyfonts works?

A file created with Skyfonts fonts shows the font family in square braces with (OTF) appended and substitutes default font, rather than making use of the identically named font file, sitting in c:\windows\fonts\ on PC / Font Book on Mac.

Same result if the font files are dumped in a Document fonts subfolder next to the InDesign file.

Troublingly, using a different font cloud sync app (or in the rare instance where the font is available on fonts.adobe.com) doesn't remove the issue - InDesign lists those in its font family menu without the square braces and (OTF) appended.