RDS Cluster - Intermittent "No available computers in the pool"

We have deployed a second RDS cluster and are in the process of migrating the VMs from the old WinServer 2016 based cluster to the new 2019 based cluster. Occasionally we see the error "There are no available computers in the pool. Try connecting again or contact your network administrator."

Most of the time they can successfully reconnect after another attempt or two. Occasionally they have to wait a few minutes but can generally reconnect after some time. The old cluster does not exhibit this behavior and I cannot find good resources on what to investigate to alleviate this problem.

Suggestions?