Can't write in Hebrew in text boxes on a PDF

Dear Community,

I got a PDF file for a training I am delivering. We have a few places in that file, where participants can fill text boxes. When trying to fill the text box in English, everything works fine. When I try to fill it in Hebrew letters - nothing happens ot I have on screen very small shapes like bullets. 

I ticked the "right-to-left" options in the prefrences, restarted the reader and my computer - it didn't help.

I don't have the PRO version, I have Win10...

Can it be a matter of fonts maybe?

This is very urgent for me.

Thank you so much,

M