Thank you, I wasn't clear - I wanted OTF as text, but nevermind 
I have just two suspicions, one of which you could check easily as well:
1) wrong font in the form (look for FC OTF commands preceding the corrupted text - whether correct Cyrillic font is being selected).
2) the form manipulates text somehow incorrectly (this one somebody could try to debug, but I have no idea how to do that from within portal preview call...)
Since you now have some Cyrillic in PDF, the SAP printing environment should be set up, so I think, the rest is something for SAP. Their form, their debug exercise.
cheers
Jānis