I am facing a problem in Windows 10, as it is not substituting 3~4 Diacritics on one base character, and also not replacing the Long shape of Initial as required. This feature and substitution is working Fine with windows 7, as required.
I have created and attach here a sample font to understand the issue for Font developers, as its working in Windows 7, but not working in Windows 10. I tested it with Word2013, Notepad & Wordpad. All having same problem.
Also attaching the result of Windows 7 and Windows Pro 10.