Custom ISharedDataSourceResolver no longer works in v19.2.25.813

[Robin]

Based on our issue from 2 years ago, we implemented ISharedDataSourceResolver as a fix: https://www.telerik.com/forums/pass-user-claimsprincipal-from-reportscontroller-to-webservice-datasource-controller

    public class CustomSharedDataSourceResolver : Telerik.Reporting.Processing.Data.ISharedDataSourceResolver
    {
        /// <summary>
        /// Resolves and returns a DataSource instance from the provided <paramref name="sharedDataSourcePath"/> parameter.
        /// </summary>
        /// <param name="sharedDataSourcePath">The value of the Path property obtained from the report definition. Might be relative or absolute.</param>
        /// <returns></returns>
        public DataSource Resolve(string sharedDataSourcePath)
        {
            ValidateConfiguration();

            var absolutePathToSharedDataSourceDefinition =
                GetExistingFilePath(Configuration.Instance.ReportsPath, sharedDataSourcePath)
                ?? GetExistingFilePath(Configuration.Instance.SharedDataSourcesPath, sharedDataSourcePath);

[...]

It is registered in our Appsettings.json:

{
  "ConnectionStrings": {[...]},
  "AllowedHosts": "*",
  "AzureStorageBlobConfig": {[...]},
  "Logging": {[...]},
  "TelerikReporting": {
    "Processing": {
      "SharedDataSourceResolver": {
        "Provider": "custom",
        "Parameters": [
          {
            "Name": "typename",
            "Value": "TgsFlow.Plugin.Reporting.TelerikReporting.Utilities.CustomSharedDataSourceResolver, TgsFlow.Plugin.Reporting.TelerikReporting"
          }
        ]
      }
    }
  }
}

If I put a breakpoint on Resolve(), this breakpoint is hit on version 18.2.24.806 of Telerik.Reporting.Services.AspNetCore and Telerik.WebReportDesigner.Services. But if I upgrade those dependencies to 19.2.25.813 the breakpoint is no longer hit and the previously discussed fix no longer works.