I tried to reproduce the problem in the attached Radzen app to no avail. The page parameter was correctly passed. Make sure your OrderMaintenance page does not require more parameters - optional parameters are not supported. BlazorPageParameters.zip (28.0 KB)
I asked you to check if that page is not using other parameters from other locations. This can be verified by inspecting the generated code - XXX.razor.designer.cs - check how many properties are decorated with [Parameter]
This page does not have any parameter declared which is why it ends up with 404. Can you send us the declaration of the other page - the one that navigates to it? The JSON of the page should suffice.
Unfortunately we can't determine the cause of the problem. We will need your complete application in order to test it locally. You can send it to info@radzen.com. Delete the server/bin, server/obj and wwwroot directories in order to keep the attachment size within limits. Alternatively use a hosting service (Google Drive, OneDrive etc.)