Given the behavior specified in the current version of the SDAM specification, it's possible for get-more/kill-cursor requests to fail in the following scenario:

• Create MongoClient with a seed list with IP addresses for a replica set with host names as normal DNS names.
• Execute a query with a non-primary read preference
• Execute a get-more for that query

This can happen because server selection will succeed against a seed list host that reports itself as a secondary, but by the time the get-more executes, the primary has identified itself and the driver has replaced all the ip-address-specified seed list hosts with the host names from the primary's server description. The result is that server selection fails for the get-more, as the topology has "forgotten" about the seed list hosts.

See https://github.com/mongodb/specifications/commit/5a4005f0bb97ff5238e3a67501ec2ece64326a4f for the formal specification of this enhancement.