Question on Chopin Nocturne 20

I have been learning this piece with my teacher, I have the Henle Urtext for Chopin's nocturnes so in theory it should be a pretty definitive interpretation. In the second "part" my sheet music shows the right hand as transitioning to 3/4 time while the left hand stays in 4/4. It is 3/4 where every measure is half of the measure of the left hand, very strange to look at. But every performance I can find, even of legendary performers, has them playing it completely straight as if the time signature did not change. They play it more like https://musescore.com/classicman/scores/77131 this score I found. What is going on??? How should I be playing it??