Symptoms
Assume that you configure Transactional Replication or enable Change Data Capture (CDC) feature for the database in SQL Server 2016 or 2017. When there are multiple publisher databases on the same instance of SQL Server, you may experience severe performance issues with the REPL_SCHEMA_ACCESS wait type.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This issue is fixed in the following cumulative updates for SQL Server:
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:
References
Learn about the terminology that Microsoft uses to describe software updates.