Iphone 8plus, was stuck in ios 12 since a couple of years ago. Couldn't update directly from phone, got the "not connected to the internet" thing. Tried removing passcode, reset network settings, and reset all settings, nothing works. Finally downloded ios 14.3 using itunes. At first installation I got error 4000, then I tried removing passcode from the phone and that was it. Good luck everyone.

Iphone 8plus, was stuck in ios 12 since a couple of years ago. Couldn't update directly from phone, got the "not connected to the internet" thing. Tried removing passcode, reset network settings, and reset all settings, nothing works. Finally downloded ios 14.3 using itunes. At first installation I got error 4000, then I tried removing passcode from the phone and that was it. Good luck everyone.