English appears to be a second language for him.
He's very good at it. Interestingly, he seems to have a european accent, but not all of it is a foreign accent. I can't tell if that is because he somehow learned a European English accent [of which there are many], or if it is just the accent left over from his first language. In the vast majority of cases, learners of English end up learning American English, for many reasons.

Hello, Jan here in Shenzhen and today I'm gonna talk a little bit about the city that I like the most.
I've been to over ninety countries and people are surprised if I say Shenzhen is *one of the most favorites …
It's one of my favorite cities in the world. It's in the top 5 for sure, maybe it's even (eh) in the top 3. And why is that?
Well, as you can see, I'm in Shenzhen right now and behind me you can see the (eh) [let me see. Where is it? It's over there.]
I think it's called the Pingan Financial Center, 600 meters high, here
in Futian District in Shenzhen. So, why do I like this city so much? I think there's only one reason for that
and that's the energy. When I came here for the first time -- it's not only in Shenzhen, it's also in Beijing and
in Shanghai -- but you can really feel the energy of this city, you can see it growing every time you come
here. I come to [EHEHEH]~ I visit Shenzhen at least once per year and every time you can see changes.
Everytime I come there is a new subway line, or they have built a new skyscraper, uhm, it keeps changing.

*"one of the most favorite" ; this is not a phrase that can be said.
...one of my favorite(s).
...one of the favorites...

The phrase "most favorite" isn't wrong, but it's very specific, and can easily be misused. In this case, it doesn't fit with the surrounding words.
That's very likely why he rephrased it in the next sentence.