WE have made changes on TEST server but it is impacted on PROD SQL server

We have 2012 SQL SERVER(PROD), client cloned a Test server from PROD, For testing the Upgrade process.

While performing the SQl server upgrade we have restarted services on TEST, after restarting the services Report server schema version is changed from 163 to 164 on PROD. We got SSRS connection issues to fix the issues we have changed the report server schema version to 163 on PROD.

We are confused that we have restarted services on TEST but report server verion changed on PROD how it happens