Yup, same problem on both 20.8.7 and 20.6.18
On 20.6.18 the gestures only work with a third party launcher, but they do not work with the stock MIUI launcher.\
On 20.8.7 it was worse, gestures wouldn't work on any launcher.
Prior to that, I had MIUI 12.0.1.0 stable and everything worked as...