Symptoms
Assume that System Center Configuration Manager (SCCM) upgrades an instance of SQL Server to SQL Server 2017 on windows. After upgrade, Change Tracking (CT) auto-cleanup process is stuck and not progressing due to which, you may notice that some of the critical tasks are blocked.
Resolution
This issue is fixed in the following cumulative update for SQL Server:
Cumulative Update 2 for SQL Server 2017
About cumulative updates for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Latest cumulative update for SQL 2017
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.