The app and flow will not currently be connected in the target environment after deployment. First associate valid connections with the flow and activate the flow. Then edit the app and re-associate the flow to the button.
I opened a case with Microsoft and they said, "Presently there is no timeline when this issue would be addressed".
Please fix this as having to back in and manually reconnect and turn on flows goes against the reason to use Azure DevOps for ALLM and CI/CD. As we cannot truly automate our Power Platform deployments.