Try going into the console tab of your service and run curl -4 ifconfig.me.

Also, make sure you're reading X-Real-IP to get the real IP from the client, not from a "middleman"/CDN.

https://docs.railway.com/networking/public-networking/specs-and-limits

Please disregard the original issue. After about an hour of digging, I ultimately discovered that my service's URL had changed from https://kokou-stats-production.up.railway.app/ to https://kokoustatus.up.railway.app/. The second link has a fully working service, while the first still updates on new pushes to my GitHub repository but fails to connect to my backend server. The second link apparently does have one of my three static IPs, which can be verified here: https://kokoustatus.up.railway.app/api/myip. I have absolutely no idea why this is happening.TLDR: The service always worked, but my domain was changed without me realizing. I should have figured this was the case, since the entire program ran properly locally, and direct calls to the third-party API in my service console had no errors.I don't know why this occurred (I do not remember ever changing my domain), but I am leaving it here in case it might be of use to the Railway team.

PLEASE DISREGARD THE ABOVE!

I definitely figured it out, and it's really silly. Basically I had just upgraded to Pro, but I had an identical version of my service up on a Hobby workspace. I was using the URL for the original Hobby app to troubleshoot the network issues and didn't realize it wasn't the Pro link until now. Both services auto-updated on commit from my repository, so I never noticed. Apologies!