Can't sign in to icloud from my devices. Segfault in iCloud pref pane. iCloud.com login works fine.

This saga started when I bought the iPhone SE. During the in-store setup process I was unable to sign in to iCloud. This is what happened:

1. Enter my iCloud email and password. Click "Next"
2. Read the terms of service. Click "Agree"
3. It tried to "verify" the account (spinning wheel)
4. After 5 seconds it kicked back two screens to the sign in page.

• Expected Behavior: iPhone setup should have logged into iCloud and continued to next screen in setup process.
• Observed Behavior: iPhone setup scrolls back to the login page with no error messages.

In store, they were so baffled by this issue that they returned the iPhone and got me a new one. The same behavior was observed with the second iPhone. In order to finish the transaction, we just skipped over the iCloud section. Later, i went into system preferences. The sign-in page from Settings app behaves in a similar manner.

1. Enter my iCloud email and password. Click "Sign in"
2. "Verifying" at the top of the screen with a spinning whee.
3. After 3 seconds, "Verifying" goes away but I am not logged in. Can click sign in button again (and same thing happens)

• Expected Behavior: iPhone should log in to my iCloud.
• Observed Behavior: Nothing happens when I click "Sign In."

Interestingly, if I enter an incorrect password it DOES give me the error. So I know my password is right. Furthermore, I am able to log in fine on iCloud.com and access my email. Then it got even worse. I called Apple Care (1800-MYAPPLE) and am now talking to a senior support specialist. They try to reset my iCloud password to see if that will do anything. As soon as they reset my password I get a bunch of popups on my Mac that say I need to sign in to iCloud. Now I go into the iCloud preferences to try and sign in on my Mac. The same issue happens. I can not sign in to iCloud anymore on the mac!

1. In settings app from my mac, open "iCloud Preferences"
2. Segfault crash

But it got worse. Pretty soon I was getting popups that i COULD NOT CLOSE from various system services they it needed my administrator password. Tons of popups. Hundreds of popups. I couldn't do any work. As soon as I closed one popup another would open. I went into Keychain Access and reset my Local Items keychain and this seemed to fix the popups.

In all: I can not log in to iCloud from ANY of my devices. The preference pane seems to encounter a segfault when attempting to log in on my Mac (and I assume it's the same bug on my iPhone). I can not get resolution from phone support, and I am about to return this iPhone since I can't use the primary feature I purchased it for (Apple Pay) without iCloud.

Any help would be appreciated. Thank you.

P.S. My iCloud account is called "Janet Perr" (my mom's name) from when I was a kid and using her account and credit card. It's not my name though and nobody (even phone support) seems to be able to change it. Very frustrating. I am NOT Janet Perr!