Issues with Outlook Update KB4493226 (March 2, 2021)?

[German]Quick question to administrators and users of Outlook 2016. Are there any issues (lags or hangs and slow reactions) after installing the update KB4493226 from March 2, 2021? I got first reports about some trouble.

Update KB4493226 f0r Outlook 2016

On March 2, 2021, Microsoft released a number of non-security updates for Microsoft Office. I had mentioned these updates in the Microsoft Office Patchday (March 2, 2021) blog post. For update KB4493226, it says that it fixes an issue in Microsoft Outlook 2016 that corrupts file attachments in Office 365 Encrypted Message Encryption (OME) messages.

This update is only available for the Microsoft Installer (MSI) based edition of Office 2016. It does not apply to the click-and-run editions of Office 2016, such as Microsoft Office 365 Home. The package is delivered automatically to affected systems via Windows Update, but can also be downloaded and installed manually from the Microsoft Download Center.

• Update 4493226 für 32-Bit-Version von Outlook 2016
• Update 4493226 für die 64-Bit-Version von Outlook 2016

You may need to restart your computer after installing this update.

Outlook has become slow and hangs

Initially I received the following feedback via Twitter. In the scenario, Outlook 2016 is being used with multiple shared mailboxes. The user is complaining about issues with the KB4493226 update for Outlook 2016.

After installing the update KB4493226, it has the problem that Outlook hangs and responds only very tenaciously (slowly). Uninstalling the patch and restarting the Windows client fixes the issues. Then I received a first feedback to the German edition of this blog post, that has been published a few hours ago – freely translated:

We can observe this behavior again and again, especially with Outlook on Windows 10 (20H2). Outlook freezes and then hangs for quite a while or does not respond at all. It acts less problematic on the remote desktop servers. And that is our standard scenario.

But it does not affect all systems. We have not yet been able to investigate the trigger further – due to the lack of time because of the current permanent problems at Microsoft on all fronts. Usually it is enough to close, count to 10 and open again…

And I received this comment, linking to the techcommunity post Outlook add-in and disk activity, addressing and issues with the Teams add-in (but the thread has startet 2019). Has anyone else noticed this after installing the non-security update?