Downgrade from 20.12.30 to 20.12.28

[Googol]

Hi, yesterday l updated my phone to version 20.12.30 (Miui Polska). It turned out that there are some problems with this version of software. Is it possible to get back to the 20.12.28 version? I have seen some posts about it but I'm not sure if they are still working. I have read that you have to do wipe (data, dalvik, cache) and then install the old version trough Twrp.
Is this method still good?
Will it wipe my all data?
I have unlocked bootloader and I don't have root. My phone is Mi9 (cepheus)
P.S. sorry for my English, I haven't used it for a long time

 

[geoorg]

Hi, yesterday l updated my phone to version 20.12.30 (Miui Polska). It turned out that there are some problems with this version of software. Is it possible to get back to the 20.12.28 version? I have seen some posts about it but I'm not sure if they are still working. I have read that you have to do wipe (data, dalvik, cache) and then install the old version trough Twrp.
Is this method still good?
Will it wipe my all data?
I have unlocked bootloader and I don't have root. My phone is Mi9 (cepheus)
P.S. sorry for my English, I haven't used it for a long time

Dirty flash 20.12.28
If it doesn't boot then format data

 

[Googol]

Dirty flash 20.12.28
If it doesn't boot then format data

20.12.28 is based on android 10 and 20.12.30 on android 11. Won't that be a problem?

 

[geoorg]

20.12.28 is based on android 10 and 20.12.30 on android 11. Won't that be a problem?

Then do a factory reset from twrp (this will keep your internal storage)
Then flash rom
Clear cache and dalvik
Delete "data/system/package_cache"

Reboot

 

[Googol]

Then do a factory reset from twrp (this will keep your internal storage)
Then flash rom
Clear cache and dalvik
Delete "data/system/package_cache"

Reboot

Ok, I have 2 questions.
1. Will factory reset wipe data from my apps, photos, music…? If so, which backups would you recommend for devices without root. Or would it be better just to copy these things to the computer?
2. Where can I find "data/system/package_cache"? Should I delete this being in Twrp or in files app?

I'm really thankful for your help man. To be honest, I'm a newbie in these rom flashing things and I don't want to mess anything up.

 

[geoorg]

Ok, I have 2 questions.
1. Will factory reset wipe data from my apps, photos, music…? If so, which backups would you recommend for devices without root. Or would it be better just to copy these things to the computer?
2. Where can I find "data/system/package_cache"? Should I delete this being in Twrp or in files app?

I'm really thankful for your help man. To be honest, I'm a newbie in these rom flashing things and I don't want to mess anything up.

1, factory reset will remove all your apps. Photos and music will not be deleted.

2. You can find that by booting to twrp
Advanced > file manager

 

[Poney70]

20.12.28 is based on android 10 and 20.12.30 on android 11. Won't that be a problem?

20.12.28 is based on Android 11 (for Mi 9 "cepheus")... Don't know why you said 10...

 

[Googol]

20.12.28 is based on Android 11 (for Mi 9 "cepheus")... Don't know why you said 10...

Yeah sorry, my bad. Btw everything went great, just like you said. Thanks again