Since the request is coming from a Machine, you can try using http://_api.internal:4280/ as the API endpoint. It’s a bit unclear what endpoint your app is calling when getting the EOF. Are you listing machines? Or creating machines?
We were able to resolve that error and it should no longer be happening. A host had been offline for a couple months came back online and our system components were outdated.
I can’t provide much help here as the error is really not much for us to go on but it does look like your app has a lot of machines (>5k) which can be an issue when trying to constantly list machines as appears to be happening from out telemetry (screenshot below).