This is related to deploy request slowness. Adding a region triggers a full release cycle, just like when you deploy a new image.
Service discovery has gotten slow as we’ve scaled. We’re in the process of rebuilding it, because this stuff should be much faster. So bear with us for a few days.
You can work around this if you’re changing regions frequently. If you scale the app up with flyctl scale count 3, then flyctl regions add <code>, it should keep older instances alive long enough to prevent slow requests. You can then scale back down to 1. It’s not ideal, but it’ll work!