Requesting a token with the offline_access scope in Duende IdentityServer v7 results in ArgumentNullException

[DougB-HCHB]

Below is what was logged. If I submit the exact same request without the offline_access scope, the error does not occur.

2024-02-27 16:27:39.914 [Serilog] [Error] [30] [Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware]
[Serilog] An unhandled exception has occurred while executing the request.
[Serilog] System.ArgumentNullException: Value cannot be null. (Parameter 'PartitionKey')
   at Azure.Core.Argument.AssertNotNull[T](T value, String name)
   at Azure.Data.Tables.TableClient.UpsertEntityAsync[T](T entity, TableUpdateMode mode, CancellationToken cancellationToken)
   at ElCamino.IdentityServer.AzureStorage.Stores.PersistedGrantStore.StoreAsync(PersistedGrant grant, CancellationToken cancellationToken)
   at Duende.IdentityServer.Stores.DefaultGrantStore`1.StoreItemByHashedKeyAsync(String hashedKey, T item, String clientId, String subjectId, String sessionId, String description, DateTime created, Nullable`1 expiration, Nullable`1 consumedTime) in /_/src/IdentityServer/Stores/Default/DefaultGrantStore.cs:line 231
   at Duende.IdentityServer.Stores.DefaultGrantStore`1.CreateItemAsync(T item, String clientId, String subjectId, String sessionId, String description, DateTime created, Int32 lifetime) in /_/src/IdentityServer/Stores/Default/DefaultGrantStore.cs:line 177
   at Duende.IdentityServer.Stores.DefaultRefreshTokenStore.StoreRefreshTokenAsync(RefreshToken refreshToken) in /_/src/IdentityServer/Stores/Default/DefaultRefreshTokenStore.cs:line 43
   at Duende.IdentityServer.Services.DefaultRefreshTokenService.CreateRefreshTokenAsync(RefreshTokenCreationRequest request) in /_/src/IdentityServer/Services/Default/DefaultRefreshTokenService.cs:line 222
   at Duende.IdentityServer.ResponseHandling.TokenResponseGenerator.CreateAccessTokenAsync(ValidatedTokenRequest request) in /_/src/IdentityServer/ResponseHandling/Default/TokenResponseGenerator.cs:line 453
   at Duende.IdentityServer.ResponseHandling.TokenResponseGenerator.ProcessTokenRequestAsync(TokenRequestValidationResult validationResult) in /_/src/IdentityServer/ResponseHandling/Default/TokenResponseGenerator.cs:line 335
   at Duende.IdentityServer.ResponseHandling.TokenResponseGenerator.ProcessAsync(TokenRequestValidationResult request) in /_/src/IdentityServer/ResponseHandling/Default/TokenResponseGenerator.cs:line 107
   at Duende.IdentityServer.Endpoints.TokenEndpoint.ProcessTokenRequestAsync(HttpContext context) in /_/src/IdentityServer/Endpoints/TokenEndpoint.cs:line 133
   at Duende.IdentityServer.Endpoints.TokenEndpoint.ProcessAsync(HttpContext context) in /_/src/IdentityServer/Endpoints/TokenEndpoint.cs:line 81
   at Duende.IdentityServer.Hosting.IdentityServerMiddleware.Invoke(HttpContext context, IdentityServerOptions options, IEndpointRouter router, IUserSession userSession, IEventService events, IIssuerNameService issuerNameService, ISessionCoordinationService sessionCoordinationService) in /_/src/IdentityServer/Hosting/IdentityServerMiddleware.cs:line 106
   at Duende.IdentityServer.Hosting.IdentityServerMiddleware.Invoke(HttpContext context, IdentityServerOptions options, IEndpointRouter router, IUserSession userSession, IEventService events, IIssuerNameService issuerNameService, ISessionCoordinationService sessionCoordinationService) in /_/src/IdentityServer/Hosting/IdentityServerMiddleware.cs:line 128
   at Duende.IdentityServer.Hosting.MutualTlsEndpointMiddleware.Invoke(HttpContext context, IAuthenticationSchemeProvider schemes) in /_/src/IdentityServer/Hosting/MutualTlsEndpointMiddleware.cs:line 95
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Duende.IdentityServer.Hosting.DynamicProviders.DynamicSchemeAuthenticationMiddleware.Invoke(HttpContext context) in /_/src/IdentityServer/Hosting/DynamicProviders/DynamicSchemes/DynamicSchemeAuthenticationMiddleware.cs:line 51
   at Duende.IdentityServer.Hosting.BaseUrlMiddleware.Invoke(HttpContext context) in /_/src/IdentityServer/Hosting/BaseUrlMiddleware.cs:line 27