NSwag fails on endpoints accepting a DateTime

Adding this endpoint:

[HttpGet("[action]")] public async ValueTask Test(DateOnly d) { }

Causes NSwag to fail with this error:

Severity Code   Description Project File    Line    Suppression State
Error       NSwag command line tool for .NET Core Net70, toolchain v14.0.2.0 (NJsonSchema v11.0.0.0 (Newtonsoft.Json v13.0.0.0))
 Visit http://NSwag.org for more information.
NSwag bin directory: C:\Users\john\.nuget\packages\nswag.msbuild\14.0.2\tools\Net70
Executing file 'nswag.json' with variables 'Configuration=Debug,OutputPath=bin\Debug\net7.0\,CSharpOutputPath=C:\StrangeCloud\StrangeCloud.Api\..\StrangeCloud.Service.Client.CSharp\Generated,TypescriptOutputPath=C:\StrangeCloud\StrangeCloud.Api\..\StrangeCloud.Service.Client.Typescript'...
Launcher directory: C:\Users\john\.nuget\packages\nswag.msbuild\14.0.2\tools\Net70
System.InvalidOperationException: Error while rendering Liquid template TypeScript/AxiosClient:
Error while rendering Liquid template TypeScript/Client.RequestUrl:
Object reference not set to an instance of an object.
---> System.InvalidOperationException: Error while rendering Liquid template TypeScript/Client.RequestUrl:
Object reference not set to an instance of an object.
---> System.NullReferenceException: Object reference not set to an instance of an object.
at NSwag.CodeGeneration.TypeScript.Models.TypeScriptParameterModel.get_GetDateTimeToString() in /_/src/NSwag.CodeGeneration.TypeScript/Models/TypeScriptParameterModel.cs:line 78
at Fluid.Accessors.PropertyInfoAccessor.Invoker`2.Invoke(Object target)
...etc...

Removing the endpoint makes it work again. Any idea what I'm doing wrong? NSwag supposedly supports DateTime params.