Q: Why is iTunes keeping on saying this computer is no longer authorized for apps... Would you like to authorize...? It almost never authorizes. Computer browser login works, iTunes menu login worked but try to sync get same question - doesn't authorize

I have a Windows 10 computer and an iPhone 6s Plus current iOS (9.3.2).

I've tried different suggestions from the communities including deauthorize all computers and then reauthorize and something that had me delete a file on my computer in case it was corrupt.

The symptoms are the same no matter what.

I can log in to my apple.com account with a browser and once in a while have to try a second time, but it works.

On the other hand, if I plug in my iPhone into my computer, my iTunes starts to synch and then almost always shows the message: 'This computer is no longer authorized for apps that are installed on the iPhone "iPhone name". Would you like to authorize this computer for items purchased from the iTunes store?'

I click Authorize and the next screen shows the login screen with my id filled in, I enter the password and it usually fails.

I just went to the iTunes Account menu, signed in there, and still got the message that this computer is not authorized... and that failed again.

It fails most times, but once in a while it clears the authorization and will sync.

It's done this as long as I can remember, even back with my iPhone 4.