I'm experiencing kind of weird error, I'm calling API (which written in golang) to get access token, that API returns the correct value for one time but if I send that API call again it returns 502 error code, then if I call that API once again it will return the correct value. this happens one after the other.
Looks like issue happened because of the load balancing. Normally round-robin routing policy is used in load balancing. For example, if you have two servers one request goes for the first one and other one goes for the other server. So for your question, the first request is going for the working server and other is going for the non-working server. Check whether your other servers are working properly.