Symptoms
Assume that you run DBCC CHECKDB command against a table in Tempdb in Tempdb Memory-Optimized Metadata mode in SQL Server 2019. If the table was created in the same transaction (e.g. within an explicit BEGIN TRAN … COMMIT TRAN) as that of DBCC CHECKDB, an access violation may occur when you attempt to fetch the Index Allocation Map (IAM) page of the table.
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:
References
Learn about the terminology that Microsoft uses to describe software updates.