I tried cloning a flow from Sandbox to Prod on the EU platform.
I followed all the steps and configured the connections (using existing Prod connections). But after completing the setup, I’m redirected to a 404 page, and the deployment doesn’t go through.
I attempted to reproduce the Sandbox → Prod deployment on EU and wasn't able to trigger the 404 so far. Can you try once again and let us know if it works fine now? It might be an intermittent issue.
That being said, I've reached out to our teams internally to further investigate and you should hear from us when we have something concrete.