Shared Mailboxes or Calendars not updating since mid Jan 2022 unless disable Shared Mailbox Caching

[gblackburn]

Hello.

We're an MSP and since around 17th/18th Jan we've had one or two users in 7 different companies (tenants)  report issues with shared mailboxes or shared calendars they have access to not updating.

We've been able to get working again by simply unticking option in Outlook profile to cache shared mailboxes. 

But with this amount of clients with the same issue, I've not been able to see anything regarding known M365 health / windows update issue that causes this in the last few days.  Anyone else seen this issue and know root cause or have any acknowledgement of known issue 

[#2]

Same problem here running Office 365 Monthly Channel 2112 v. 14729.20322. UN-checking "Download shared folders" is at this moment the workaround for us. How can we flag it in the O365 portal?

[#3]

We have the same issue, how can we flag it in the O365 admin portal?

[#4]

@gblackburn Something that worked for me:

As others have done, disable caching shared mailboxes AND disable the "shared calendar improvements" option.  Restart Outlook, then enable only the caching of shared mailboxes, because clearly the "shared calendar improvements" aren't.

All my sync errors have cleared up and the shared folders are updating again.

Whatever these "improvements" are, they should probably take it back to the lab.  And if anyone knows of a way to get this back to the team that is no longer investigating this issue, please test it out and feel free to do so.

Best of luck

[#5]

Found a working workaround
1_Disable Shared Mailbox Caching
2_Open Outlook and verify shared folder works online
3_Enable Shared Mailbox Caching
4_Open Outlook in Safe Mode (outlook.exe /safe)
5_Pres Shift-F9 on shared mailbox and wait until mailbox completely synchronize. Now verify new mails arrives and showed automatically.
6_Close Outlook (safe mode) and re-open normally, recheck outlook shows new upcoming emails normally.

[#6]

Interesting. This seems to confirm that the problem is with the cache itself and rebuilding resolves it. I would think the risk of a repeat offense is high. So please do reply again if you find the problem returns after using that workaround.

[#7]

Many people have, it's earlier in the thread. The problem returns intermittently. I've been monitoring the Sync Issues folder in Folder View more often now and get two a day after the "fix" above.

[#8]

@Jeremy Bradshaw we can confirm that this fix either doesn't stick for more than maybe a day or simply doesn't work at all. Everything from toggling all of the cached mode settings to making a new profile to online repairs to full reinstallation of Office has not been effective in solving this. It is only affecting users that have delegated access to user mailboxes in our experience so far.

[#9]

@gblackburn We are affected too, and find it pretty incredible that Microsoft has "suspended" investigation of this issue EX316072.  "FInal Status: We're awaiting additional system logs from affected users' profiles to assist with the investigation.  Please contact support for further details on how to collect the requested data and once it has been collected we'll resume our analysis of the issue."

[#10]

@gblackburn I was facing the same issue. Disabling the cache did not help (for calendars). What magically solved the issue on my side was disabling the Microsoft 365 features:

[#11]

hi all

see this link.. I opened a case few weeks back in feb and after some wait, this seem to be fixed now  https://support.microsoft.com/en-us/office/shared-mailbox-is-not-automatically-refreshing-for-new-em...

[#12]

This solution has worked great for us.  The customer has high user shared inboxes that just weren't updating as quick as they needed them.

https://helpwise.io?via=networkplumber

[#13]

@nseh17 This worked perfectly for me.

[#14]

******* FINALLY I FOUND A PERMANENT SOLUTION FINALLY ******



1. Connect to Exchange Online With PowerShell

PowerShell:

Connect-ExchangeOnline

Set-OrganizationConfig -OAuth2ClientProfileEnabled $true



2. Regedit Users Computer

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Common\Identity

Add DWORD 32:

EnableADAL

Hex Vaule:1


Close Outlook 365 reopen and there you go.