Failing to write to database only in a replica set configuration, read is working fine. Also works fine in 2.4.3. Looks life failing to select the primary instance.

Full stack trace

{{2.4.2 :006 > client[:contacts].insert_one(

)
Mongo::Error::NoServerAvailable: No server is available matching preference: #<Mongo::ServerSelector::Primary:0x14987080 tag_sets=[] max_staleness=nil> using server_selection_timeout=30 and local_threshold=0.015
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/server_selector/selectable.rb:115:in `select_server'
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/cluster.rb:246:in `next_primary'
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/retryable.rb:150:in `legacy_write_with_retry'
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/retryable.rb:103:in `write_with_retry'
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/collection.rb:422:in `block in insert_one'
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/client.rb:485:in `with_session'
from /usr/local/rvm/gems/ruby-2.4.2/gems/mongo-2.5.0/lib/mongo/collection.rb:421:in `insert_one'
from (irb):6
from /usr/local/rvm/rubies/ruby-2.4.2/bin/irb:11:in `<main>'
2.4.2 :007 > exit}}