Exchange Account Keeps Disappearing from Internet Accounts on macOS Mojave

I'd been having this problem, too, this week, and wound up chatting with Apple support about it. They said a new internal document today was suggesting the screen recording, and set up a call for later today after I'd made the recording.

But actually, once the support desk called me to connect me with engineering, they were able to help me fix it without escalating it further. They had me reset my keychain completely, then restart the computer. Once I did that, I was able to re-add the Exchange account, authenticate with third-party oAuth, and even turn iCloud Keychain back on. So far, seems to be working well.

Hopefully they'll have pushed a new update out before the next time I have to change my Exchange password, which I think is partly what triggered this whole glitch on my end. Good luck to anyone trying it for themselves, too!

This is what I've tried now:

1. Logged out of iCloud
2. Added the account back
3. Logged back into iCloud

And... no luck. Account stuck around for about 10 minutes and is gone again.

I suspect this is due to choosing yes to remove the account from all computers since this computer worked fine until I clicked that button yesterday after having issues on another computer. Since then I haven't been able to get the account to stick for more then 30 minutes.

Here is what I did. So far, so good. The steps I followed were that I

1. turned off keychain in the iCloud preferences,
2. deleted all keychains with exchange in its name (those related to Exchange only),
3. deleted Exchange from both my Mac and my iPhone,
4. turned on keychain in the iCloud preferences,
5. added in my Exchange account on my mac using one email address associated with my account, then
6. added in my Exchange account on my iPhone using another email address associated with my account.

I have two email addresses associated with the same email account in Exchange (I send and receive from and to the same account using two different email addresses).

Like I said, this has worked for me so far.

I found success with only one of your steps, like the Hope Diamond shimmering among of pile of mined ore. Having never reset Keychain or turned off the iCloud Keychain, I only:

1. Added back the Settings / Internet Account for Exchange but *omitted Contacts*
2. Opened Contacts
3. In Contacts, on the menu, selected Preferences / Accounts tab / Exchange item, and checked "Enable this account"
4. That took me back to Settings / Internet Accounts where I checked on the Contacts checkbox for Exchange

I was just about to post nearly the same conclusion. They had me reset the NVRAM and boot into safe mode to try to figure this out. In safe mode it worked fine so I wiped my account and created a new one. Signed into iCloud and started setting everything back up. It worked great until a minute ago when whatever is happening in the background happened again. I was trying to add a delegate calendar from Exchange and something flipped out and now the account is gone again. At this point I'm pretty frustrated since I have about 3 hours into resolving this.

I have stumbled upon some more information about this.

While researching another issue, I found that I couldn't create app passwords in O365/Azure AD much like how you aren't allowed to. After disabling and then re-enabling MFA the app password creation issue was resolved and I could create an app password.

As a test I chose Configure Manually in the Exchange Internet Account wizard and used the app password. I was able to connect and the account has stuck around for over an hour now. I was also able to enable it on my Mac mini without issue.

Unfortunately this doesn't help you right now but perhaps it will be useful for getting Apple to figure out what is going wrong.

I can now confirm that I my O365 account has not been removed in well over an hour after configuring it with an O365 App password. This seems to be the correct temporary workaround until Apple resolves this issue permanently.

Moe, I did that but was surprised to see that after disabling Keychain in iCloud and adding my Exchange account, within a few minutes the Exchange account disappeared and Keychain was re-enabled. Tried again but this time did not add the Exchange account and Keychain still re-enabled itself again. Maybe a separate issue or could be related?

Did anyone get anywhere with support on this? I can confirm it is linked to iCloud keychain with exchange Modern Auth enabled. To be honest the first support rep didn’t know what oAuth was.

My support experience has been very poor so with Apple. Slow and asking quite silly questions even after console logs provide on the issue showing a timeout and exchange account being removed. Requested escalation and if this will be fixed in the next incremental update.

Got quite a few machines with this issue and so far the only creditable response I have received was, reinstall 10.14...

Appreciate the troubleshooting steps, but come on, handed the logs and walked them through the issue.

All, has anyone solved this? I haven't seen a reply in a week and I am having the same issue. If you have it figured out, I'd love to know what the solution was (other than permanantly disabling keychain). Anything official from Apple? Are they recognizing this as an issue yet?