When generating a C# client for an API, where a model has the same name as a part of its namespace , the compiler would raise CS0118 ("'XY is a namespace but is used like a type'") on various locations in the generated code.
E.g.
Response model "Subscription" generated as part of an API client in namespace "Whatever.Application.Subscription.Client"

As a workaround one can use the fully qualified type name to correct the generated code. That has the drawback that it would get overwritten permanently when the clients are being regenerated though.

Kiota Version 1.13.0