Thank you very much for having a look at this.
Actually I am pretty sure that my font has a PostScript name since I’ve set all name fields in FontForge (see Screnshot below).
I’ve also checked your Section 7 and all Font names are identical (I have checked 4 different fonts and they all don’t work).
I would be very happy if you could try it out yourself using my project files: https://www.dropbox.com/s/4j9u4gymtbyz08s/font-embedding-not-working.zip?dl=0
Thank you very much for your help and support. It’s much appreciated.