Time stream- blazor app throws " Failed to discover the endpoint for the request. Requests will not succeed until an endpoint can be retrieved or an endpoint is manually specified."

I tried to adapt timestream .net sample console application to a blazor wasm web application. Console application runs the query succesfully but blazor app cannot with the same settings. This is my query client config:

  var queryClientConfig = new AmazonTimestreamQueryConfig
                    {
                        RegionEndpoint = RegionEndpoint.EUWest1,
                        UseAlternateUserAgentHeader=true,
                     };
var queryClient = new AmazonTimestreamQueryClient(<key>,<secret>,queryClientConfig);

when I call the query it throws exception "Failed to discover the endpoint for the request. Requests will not succeed until an endpoint can be retrieved or an endpoint is manually specified."

 QueryResponse queryResponse = await queryClient.QueryAsync(queryRequest);

I tried with and without UseAlternateUserAgentHeader.

What configuration am I missing?