While automatic updates for Microsoft 365 ProPlus are downloaded and installed automatically by default, there is a chance this may unintentionally get turned off at some point.

To verify Microsoft 365 ProPlus is set to receive the updates and security fixes correctly, open any Microsoft 365 ProPlus application (e.g., Word, Excel, etc) and select File > Account. Under Office Updates, you make sure you see the words “Updates are automatically downloaded and installed.” 

Note: If you do not see this text, select Update Options > Enable Updates.