iPad Pro 10.5 on reboot loop after updated to IOS 13.5. and ever since to IOS 14.71

Hi,

In have iPad Pro 10.5. After updating to iOS 13.5 my iPad is on a constant re-boot loop every 3-5 min.

I've tried different options even the restore to factory settings but the iPad is still on the reboot loop.

It has been happening for sometime, but I can normally get it restored.

I contacted Apple support in June 2021 and they managed to to restore it to factory settings when I first could not. It worked perfectly for a couple of months, then it occurred again in August 2021 and I phone Apple and they could not fix it over the phone. I had to wait until September for the Apple Store to reopen because of covid. Stupidly I had allowed the device to run flat rather than spend a month rebooting. As such the "Genius Bar" worker decided that it was the battery and declared the device 'dead' and showed me that on her diagnosis software. You can imagine my surprise when I get home and the iPad easily charged and I could once again do a restore albeit unsuccessful.

What I do:

1. connect my iPad Pro to my MacBook Pro and open finder
2. press and hold home button and power on iPad Pro until I get the restore screen
3. click 'restore' rather than 'update'
4. confirm 'update' on the next window
5. wait until it has downloaded the new IOS (note: the iPad behaves normally through this whole process)
6. MacBook notes on screen "Your Mac is updating the software on this iPad" and the iPad shows the apple logo and the progression of the update
7. MacBook notes on screen "Your iPad has been updated and is restarting. Please leave your iPad connected. It will appear in the sidebar after it restarts"
8. The iPad restarts into a reboot loop and does not show on the sidebar

Over to the collective wisdom of this community. Any kind suggestions or answers?

It alway occurs after restoring and updating the IOS, but before restoring any back up, so i believe it is the IOS updates, but Apple rejects this.

How can I fix it? please help.

Kind regards