Hi @Jerrick 
Your case is a bit different in that the replay failures seem to be related to the fact that machines in your replay target app having different sets of public port definitions from each other. Some of them overlap with each other – for example, there are two different machines defining port 443 in a slightly different way – and in this case the proxy may not be able to decide which definition it should pick, causing intermittent replay errors depending on exactly which one becomes picked.
The proxy expects that all machines in an app servicing a certain port have more or less the exact same service definitions. So, for example, an external port should map to the same internal port and vice-versa, with the same set of handlers. A mismatch is allowed temporarily during a deployment, but should not be something permanent. If your machines are expected to expose different sets of ports, and are expected to belong to different customers, we recommend using an app-per-customer architecture (Per-User Dev Environments with Fly Machines · Fly Docs) both to improve isolation (machines in one app can still access each other!), and to make sure proxy behaves predictably when routing requests / replays.