503 + NR due to the inconsistency between the order in which the configuration takes effect and the order in xDS push

We currently use a control plane software to dynamically create clusters and routes. However, in practice, we have found that if we create a route immediately after creating a cluster. For a very small period of time, requests to access the route return 503 + NR.

We speculate that the process of cluster warming causes the cluster configuration to take effect later than the route configuration takes effect. But not for sure.

I wonder if the community has encountered a similar problem? Any suggestions?