Version switching in Swagger UI with NSwag 14

[FunThom]

Hi,
I'm working on a ASP.NET WebAPI (.NET Framework 4.7.2) using NSwag. In the beginning I used NSwag 13.19 together with the aspnet-api-versioning assemblies ([https://github.com/dotnet/aspnet-api-versioning], which work fine together. If I opened the Swagger UI (SchemaType.OpenApi3), I got something like this:

Using the comboxbox in the upper right corner, I was able to choose between the defined WebAPI versions.
After I updated the NSwag assemblies to the current version 14.0.7, the combobox for switching between
versions won't be rendered anymore:

Now I got this "explore" search box, where I have to write the wanted version string into, e.g. /swagger/v1.0.json.
If I click on the "explore" button without sepcifying a version string, I only got the message "No API definition provided."
How is it possbile, to get the combobox to be rendered again? Or, if this is not longer supported, how can I list
the defined API versions of the WebAPI, if I click on the "explore" button?

I'm using the following nuget packages in the WebAPI project:

- Asp.Versioning.WebApi.ApiExplorer 7.1.0
- Microsoft.AspNet.WebApi.WebHost 5.3.0
- Microsoft.Owin.Host.SystemWeb 4.2.2
- NSwag.AspNet.Owin 14.0.7
- System.Text.Encodings.Web 8.0.0
- System.Text.Json 8.0.3

Each of the nuget packages has its own transitive dependencies as well.

I am grateful for any hint or advice.
Thanks in advance.

Best regards,
Tom