It has been observed that in our testing that for slow test variants an election can take over 15s. When a node routes a command, it will query the the replicaset monitor to know the address for a given read preference. In case no node is reachable, a timeout of 15s is used to wait before throwing `FailedToSatisfyReadPreference`, which is not a retriable error. The requested command will therefore fail. 
Ideally, we could extend the timeout on slow variants (tsan and ubsan compiled in debug mode).