So you decide to “refresh” your development environment with a copy of your production environment, but too late you discover that copying an environment over another one makes canvas apps and flows created in that environment go away.
What should you do?
Other than kicking yourself for not remembering to back up your app and flow definition, don’t do anything.
When you refresh a D365/CDS environment with a copy of another environment, the flows and canvas apps that were in the environment go away, but within a short period of time you will see a restored copy of the app and flows appear in your environment. The canvas apps will be appended with the word “restored” and the date. Flows that are restored will be turned off.
You will need to share the app again with whichever users should have access to it again.