Lettuce changes topology details during the CLUSTER NODES lookup. The self-node host and port are replaced with the values from the RedisURI.
This behavior leads (combined with the cluster node membership verification, that is enabled by default) to execution rejection when using Azure Redis Cache.
Azure Redis Cache exposes a load-balancer as main connection point that connects a random master node. The topology detail from CLUSTER NODES contains just the plain IP/port table. If a MOVED redirection happens to occur, the MOVED details contain a host and port that is not known by lettuce (because the host and port were replaced in the topology discovery) and command execution fails.