Sony xperia 1ii XQ-AT51 upgrade and downgrade

[OmarSaidi]

Using Xperia Companion we can only upgrade but downgrade is not possible at the moment? But why is it not possible to downgrade?

Sony should enable both options in Xperia Companion because if someone is not satisfied with the update, they can easily go back to their old android version without using other tools like: 

Flashtool:

Newflasher:

Im not able to roll back from Android 11 to 10.
I think there is an anti rollback protection in Android 11
Firmware version: 58.1.A.0.921
I get every time black screen with the following message:

Your Device is corrupted and cannot be trusted

But Android 11 works perfectly in Sony xperia 1ii XQ-AT51

Tools used:
1. Flashtool
2. Newflasher

[Strampke]

Xperia cannot and almost certainly will never be downgradable.

The same applies to all other brands, smartphones, TV sets, cameras etc.

That is to say, the official way.

[OmarSaidi]

Ok but the official way is weird way because:

After updating to Android 11 build-number (58.1.A.0.921), the screen resolution of my Xperia 1 II has changed from 1644x3840 to 1096x2560. In Android 10 it was everywhere 1644x3840

and has a few more problems than before!

[Monkeynmario]

Xperia Companion is flakey and like something from the 1990’s... There is no program

that will run on the new M1 Macbook Air that you can back up your phone to.

The phone in UK is £1000 , other than Google Cloud backup it’s no go with the M1 Macbook.

I am sure the pc is sitting there laughing ! Ask if Companion is written in MS-Dos..

[EMS_MO72]

Changing of the screen resolution could be an issue that happened after the update or one of the changes with the new Android 11 update, I don't know. But reverting the software version on the device that is not possible to happen on any device as i believe, and if you tried to do that with another way that will void the warranty of the phone so i think that's why they can't make it an option on the phone.

[OmarSaidi]

Google Urges OEMs To Support Android 11 ‘Rollback Protection’ Feature To Block Downgrading!

But why? If someone is not satisfied with the update, what should they do?

Android 11 removes the "wm overscan" shell command. This change is quite annoying.

We are no longer allowed to do anything with Android!

[OmarSaidi]

The screen resolution of Sony Xperia 1 II has now changed back to 1644x3840