This is how you can downgrade any app without uninstall and losing data without root.

All you need is just to setup up Shizuku then open mt manager and grant permission to began the process

There's many more videos available on yt how to setup Shizuku just watch and follow

#System_launcher

This is version 5.39.31 Lower than V5.39.35

System_launcher china 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   min api: 33
arm64-v8a

#Settings 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12

#System_interface 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12

#RegService 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   min api: 33
arm64-v8a

#CIT 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   min api: 29
arm64-v8a

#App_vault 🇨🇳

Extracted Model: #mi15 #dada
Model System: #BETA #2.0.200.12
target api: 34   min api: 29
arm64-v8a

#User_feedback #Feedback 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   min api: 23
arm64-v8a

#Compass 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 35   min api: 26
arm64-v8a

Api changes
min api: 24 > 26

#Themes 🇨🇳

Extracted Model: #mi15 #dada
Model System: #BETA #2.0.200.12
target api: 34   min api: 28
arm64-v8a

#Application_Extension_Service 🇨🇳

Extracted Model: #mi15 #dada
Model System: #BETA #2.0.200.12
target api: 34   min api: 29
arm64-v8a

1.4.0(120250409)

#Mi_Mover 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34 min api: 21
arm64-v8a

#Wallpaper_Carousel 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34 minapi: 28
arm64-v8a

#Downloads 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   minapi: 26
arm64-v8a

#Updater
#Extracted Version #HyperOS

Extracted Model: #mi15 #dada
Model System: #BETA #2.0.200.12
target api: 34   min api: 27

Changelog:
Abnormal update behavior has been fixed since 8.6.0

#File_Manager 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   min api: 26
arm64-v8a

#Contacts_and_dialer 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34 min api: 23

Works only if you have already

Weather 🇨🇳

Extracted model: #mi15 #dada
Model system: #BETA #2.0.200.12
target api: 34   min api: 24
arm64-v8a