Android 15 and One U7 problems

[TerreroD]

Since my tablet update himself, I can be able to used

Some anybody have this problem, I just try to downgrade but keep updating himself 

[realaud]

You cannot downgrade the update.  But there may be issues we can help you fix.  What are the problems you are having that make it unable to be used?  Which tablet do you have?

[TerreroD]

I do have a Galaxy Tab S8+

[realaud]

And what issues are you having?

[TerreroD]

It just reboot himself over and over until I get the back screen that yu can see on the last picture

[realaud]

Ok, try this.  When it goes into the recovery partition (as showing in your photos), navigate to "wipe cache partition" using the volume buttons.  Lock in the selection with the power button, then when it asks if you are sure, navigate to "yes" and tap the power button to wipe the partition. After the partition is wiped, you will see "reboot system now" (first option - if it doesn't automatically highlight, navigate to it).  Tap the power button to reboot.  You should now be booting up normally.  Your problem is that you've been highlighting and selecting "reboot to bootloader", which is why you keep landing in the same place.  If you end up in the recovery partition again after following these instructions, next time select factory reset and then you can reset the tablet and restore your backup.

[TerreroD]

I already did that and reboot himself

[realaud]

Did what? factory reset?  That might be your only option here.

[420Richie420]

You can dowgrade by downloading the
apk of your old os and flashing your firmware Google how to do it for your model