PBI Report Builder Parameter Behavior

I am using the rdlEmbed? form of the URL to embed a PBI Report Builder report in an existing internal website. We have an existing launch page for the report that collects all the parameters.  Therefore I am using rdl:parameterPanel=hidden in the URL. When I try to run the URL using a parmater value that has not been loaded to the parameter values in the rdl, it gives me a blank sreen. So my question:  Is there a URL parameter to change this behavior? I do not want to have to maintain and load drop boxes on the existing web page and then also do it in the rdl when I am embedding the report.