NHibernate on .NET Core/.NET 6 doesn't work with Informix Driver (IfxDriver)
IBM released an Informix .NET Core Provider to be compatible as It's suggest for the .NET Core (and the new versions above like .NET 6). This provider has a new DLL which is named as Informix.Net.Core.dll... The problem is that the current IfxDriver.cs class is expecting a DLL with the previous name IBM.Data.Informix - check it: https://github.com/nhibernate/nhibernate-core/blob/master/src/NHibernate/Driver/IfxDriver.cs
My workaround was to create a custom driver (IfxCoreDriver.cs) which inheriths from the ReflectionBasedDriver.cs class.
Ideally, this should be configured without the necessity to create boilerplate/custom drivers.

Thanks @carlosfc-mendes. Is it available on NuGet?
https://www.ibm.com/docs/en/informix-servers/14.10?topic=incp-running-existing-informix-net-framework-provider-applications-using-informix-net-core-provider