Below is the screenshot of my developer org and it is not yet updated to Summer'19.
Here,  I have created a component LCompHidden which implements isURLAddressable interface, and using page reference state we get the value of the parameter, it is working perfectly in my dev org.
But the same I have implemented in a sandbox it worked fine but after few days it got updated to summer'19 release and it suddenly stoped working.
now I am not getting the parameters in the url, I have also tried copy pasting this url to the browser but that is also not giving me parameters.
Any pointers to the problem would be very helpful