Embedding Fonts in Epub - some don't display on IPad

I know that there are certain fonts that will not display on an epub file displayed on an Ipad. The InDesign file the fonts came from substituted the 2 missing fonts OK except one. If I look in the fonts folder from the epub the font is there it's also in the encryption.xml but I do not see the font displayed on IPad

btw the font is

MaturaMTScriptCapitals.otf

any help?

RD