Verification error whenever I try to sign in with my Apple ID on my iPad

Hi,

I recently restored my iPad 4th generation to factory by reinstalling iOS 10.3.3 (yes, I know it's reall old, but I can't buy a new iPad at this moment) because it was my last idea to speed it up because it was working painfully slow and when I was trying to turn off "find my device" (because it's required to restore the iPad) or Sign Out it threw be this error: "Verification Failed There was an error connecting to iCloud".

I first thought it would be solved after restoring the iPad but when it prompted be to put my apple id it threw me the same error followed by this other: "Could not Sign In There was an error connecting to iCloud".

I ended up setting the iPad without Apple id and I tried to Sign In on the Settings app but it resulted in the same two errors.

One thing I want to note is that I could Sign In to the App Store and use it without any problem, but I'm still not able to Sign In to the iPad itself (or iCloud)

Thanks in advance for the help.