The report execution has expired or cannot be found. (rsExecutionNotFound)

v-yulgu-msft thanks for your reponse, it's not changing the URL parameters I'm having a problem with, it's changing the value of a report parameter via the URL when combined with &rc:Toolbar=false.  

First execution working: http://myserver/Reports/report/myfolder/myreport?rs:Embed=true&rc:Toolbar=false&Year=2016

Second execution not working: http://myserver/Reports/report/myfolder/myreport?rs:Embed=true&rc:Toolbar=false&Year=2017

Removing &rc:Toolbar=false results in both working without issue:

http://myserver/Reports/report/myfolder/myreport?rs:Embed=true&Year=2016

http://myserver/Reports/report/myfolder/myreport?rs:Embed=true&Year=2017

I have tried redeploying the reports but that does not solve the issue, I'm seeing this on our dev, UAT and production PBIRS installations. I also tried SSRS 2017 on another server with the same result.

It seems like &rc:Toolbar=false changes the behaviour of the session for some reason, is this expected?

I was able to work around this issue by setting UseSessionCookies to false in Advanced Server Properties via SSMS.