Okay found it - the perfective instead of the imperfective... sorry.
The pronunciation of tři does not sound normal. I wrote ty, because I couldn't hear the ř-sound. I reported it.
You are right, the audio is not correct.
However, the only thing the contributors can do is to disable the exercise "Write what you hear". They aren't able to repair the audio.
Ok, that's a shame. But now I can clearly hear the ř-sound on the slow-version. But when you just listen to the normal speed-version, it's not there.
I don't really understand where snědla came from as a form... In the tables in the Notes section, it says the irregular past of jíst goes to jedl, so why isn't it jedla for Žofie here?
"jíst" (jedl) is perfective and "sníst" (snědl) is imperfective: