I tried to reproduce it for the past day and failed. It's good enough for me. I hope that it was my bug or something. I don't understand because yesterday the same code repeated the bug every time.
The problem is that i use your library in a proof of concept project of mine and the series of commands is not so simple like in your case so i had troubles extracting the code. I rearranged the code so now i can't reproduce it.
I probably removed some small part of code that caused it or changed the template file in excel editor somehow, anyway, i hope it was my bug or something. Thnx for reply.