Problem with .NET MAUI Blazor SQL app

[pyrotechnik]

Hello I have a problem with SQL application in .NET MAUI Blazor. I am creating an application according to this video.
YT
Everything works as it should with one table. But when I create another table including table2Service.cs, table2Repository.cs, table2Info.cs. I just recreate everything with a different table name. The table is created in the database, but when I try to insert data into the table I get an error:
System.NullReferenceException in System.Private.CoreLib.dll
The MauiApp1.dll program exited with code 0 (0x0).
But the first table still works as it should. I have no idea where the error is, and would be very grateful for help.
Thank you