When you run the INSERT INTO SELECT statement on memory-optimized table variables by using UDFs in Microsoft SQL Server 2016 or 2019, you may receive incorrect results.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
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: