" . . due to the consideration of stability and software experience, Xiaomi 8 and Redmi Note 4X will not continue to maintain the "experience" (beta?) version after releasing the last version of 9.8.29."
Simple, you are missing the China app store. Not included, of course.
The regular Global Beta has a different app for updating the built in Apps, the System Apps Updater.
Since I do not have the Global Beta but the xiaomi.eu, I do not have a System Apps Updater. Of course I do not have a China AppStore on it. Why? And still updates for any apps. Why? How does the app know that there is an update for her?
" . . due to the consideration of stability and software experience, Xiaomi 8 and Redmi Note 4X will not continue to maintain the "experience" (beta?) version after releasing the last version of 9.8.29."