It may be similar to the bug that was fixed for EF Models in the 6.10 release last December.
Entity Dev Version: 6.10.1189
Repro Steps
- Create a new EF Core Model.
- Use Database First.
- Accept the defaults for everything until you get to the Model Properties step in the wizard.
- Set the EF Core Version to EF Core 3.
- Set the Target Framework to .NET Framework.
- Check Use connection string from App.Config.
- Accept the defaults through the rest of the wizard.
- Save the model.
- Open the Model Settings, confirm Target Framework is set to .NET Framework, close the dialog.
- Close the model.
- Reopen the model.
- Open the Model Settings and see that Target Framework is now .NET 5.