Outlook not implemented or Limited connection warning

Hello everyone,

I'm here to share a problem I'm encountering more and more often with my customers, and perhaps find a solution thanks to your feedback.

The problem:
It only affects Office 2019 (Standard and Pro Plus). From one day to the next, Outlook stops working properly.

Impossible to send or receive emails: a “Not implemented” message appears.
In the File tab, it shows a limited connection with a suggestion to upgrade to Outlook 2016.
What I tried:
I've tested several solutions found on the Internet, but the only one that seems to work is to delete a registry key:

Copy the code
HKLM\SOFTWARE\Microsoft\Office\ClickToRun\REGISTRY\MACHINE\Software\Microsoft\SecurityManager\CapAuthz\ApplicationsEx
After a little digging, I notice that :

The rights to the CapAuthz folder disappear on their own.
By restoring these rights, the “Not implemented” error disappears.
The problem:
For some customers, the solution works, but :

For others, it doesn't work at all.
Sometimes, after a reboot, the problem comes back.
Any ideas?
Has anyone encountered this problem before, or do you have a more stable solution? I welcome any suggestions.

Thanks in advance for your help!

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