NotSupportedException while getting column information on Function Import #195

Steps to reproduce

1.- Create new Class Library project
2.- Create new ADO.NET Database First EDO connected to a Postgres 14.6 database through NPGSQL
3.- Update model from database -> add stored procedure from database ("Import selected stored procedures and functions into the entity model" checkbox unchecked)
4.- Double click on the function in the store section
5.- Click on Get Column Information.

The issue

We are trying to migrate a web forms (.NET Framework 4.6.1) project from SQL Server to Postgres. The company uses Entity Framework 6 for the creation of database first EDM's. We used NPGSQL and EntityFramework6.NPGSQL and the NPGSQL PostgreSQL Integration Extension for the creation of the new EDM's. However, when using the Add Function Import tool and trying to get column information for complex types generator, i get the following error:

"An exception of type "System.NotSupportedException" occurred while attempting to get columns information.The exception message is:The specified type is not supported by this selector."

Further technical details

NPGSQL version: 6.0.9
EntityFramework6 version: 6.4.4
EntityFramework6.NPGSQL version: 6.4.3
NPGSQL PostgreSQL Integration version: 4.1.12
.NET Framework version: 4.6.1
PostgreSQL server version: 14.6
Operating system: Windows 10