Translation:No Turkish people walk away from behind us.
From behind us, no Turks are walking away. And No Turkish are walking away from behind us. - were not accepted. And I think, that the Duo answer NOT Turkish is wrong. It should be NO Turkish.
Sorry, I don't like either of those versions. "No Turks are walking away ... " means something like "Turks would never, ever, walk away ... ". But that is not what is being said here.
What is being said is some people are walking away from behind us, but those people are not Turks.
It looks like this sentence cannot be translated using the logic of the Hungarian sentence (at least I can't). It needs to be changed a little bit:
"The people walking away from behind us are not Turks." - this is my best guess.
I think, we need more brainstorming from others to clear the sentences. We just began with it.
How often do native speakers actually use words like mögülünk? I have never ever used the Czech equivalent, so I'm just wondering. In my spoken Hungarian I have only used words like mögöttük and körülötted so far.
It's the only option when you want to say "from behind us". The reason it's not used much is because "from behind us" doesn't come up a lot in everyday conversation, but when it does, this is what you have to use.
I believe other languages would probably split this into two or more bites.
At least I would, in German.
There are different people behind us, some are walking away [from us], but (not) the Turks (are not moving).
The English is incorrect, but it doesn't seem possible to report it; I would suggest "No Turks walk away from behind us" as being a correct translation.