SQL alwayON on machines with two SQL instances

I have two SQL servers with two instances each (2012 and 2016), both machine are in windows 2012 fail over cluster. I am able to have the named instance (2016) created Alwayson group and the listener with a port 5023. it works fine. but I cannot get the default instance to have the AlwaysON group working, the AlwaysOn group created and the listener created on 5022(later tried 5024....), but the secondary always shows disconnected. I tried swap the two nodes for primary and secondary, no luck.

replica_server_nameendpoint_urlconnected_state_desclast_connect_error_descriptionlast_connect_error_numberlast_connect_error_timestamp
mySecondaryServer    TCP://mySecondaryServer.esclhin.on.ca:5024DISCONNECTEDNULLNULLNULL

myPrimaryServer TCP://myPrimaryServer .esclhin.on.ca:5024CONNECTEDNULLNULLNULL

Does it support two instances on a machine for AlwaysON group?