Hi,
Thank you for the detailed description, I understand how confusing this alert can be.
This message in Outlook usually appears when your Microsoft 365 apps are out of date or not fully updated to the latest supported version.
To resolve this, please follow the steps below to update Office:
Open any Microsoft 365 app, for example Word or Excel.
Click File.
Select Account.
Under Product Information, click Update Options.
Choose Update Now.
Allow the update to complete fully, then restart your computer.
If you are using Outlook on its own, you can also try the following repair option:
Open Control Panel.
Go to Programs and Features.
Select Microsoft 365.
Click Change, then choose Online Repair, which helps fix missing or outdated components.
In most cases, once the updates or repair are completed, the yellow warning bar in Outlook will disappear.