Symptoms
Assume that you use SQL Server 2017. When you try to initialize multiple databases in a SQL Server Always On availability group (AG) by using automatic seeding, you notice that seeding for some databases may fail, and need to retry on one or more secondary replicas.
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 update 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:
Note When you use the fix, the corresponding pacemaker package must be applied in order for SQL Server on Linux to work correctly.
Workaround
To work around this issue, you can retry, use backup or use restore for initialization.
References
Learn about the terminology that Microsoft uses to describe software updates.