ChatGPT-4o refusing to translate voice to voice

Hi!

Tried the voice to voice translation on mobile as on the launch day demo. When asking it to translate Swedish into Bulgarian it says that it cannot translate between those languages. Upon talking to it in Bulgarian however, it could understand me and answered in Bulgarian. So, obviously it understands both Swedish and Bulgarian but wont translate between them. When asking why, it said that it only has limited profficiency in those languages.

So what i did was that i changed the prompt to:

And now it works!

Does anyone have any idea why it does this?

Cheers