Can't add new overcloud compute node due to introspection issue

Issue

• We can see in the output of openstack overcloud node introspect 999329ab-0303-4b7c-b4e4-ce3e9af39dcb --provide that our node is failing to establish connection to https://10.103.2.11:13050.

(undercloud) [stack@ospd ~]$ openstack overcloud node introspect 999329ab-0303-4b7c-b4e4-ce3e9af39dcb --provide
Waiting for introspection to finish...
Started Mistral Workflow tripleo.baremetal.v1.introspect. Execution ID: 227c545b-9cda-4a92-a3d1-eeb1b0ff376f
Waiting for messages on queue 'tripleo' with no timeout.
Failed to run action [action_ex_id=cf4ee71e-b507-4e6f-8d27-33622c2331a2, action_cls='<class 'mistral.actions.action_factory.BaremetalIntrospectionAction'>', attributes='{u'client_method_name': u'introspect'}', params='{u'uuid': u'999329ab-0303-4b7c-b4e4-ce3e9af39dcb'}']
 BaremetalIntrospectionAction.introspect failed: Unable to establish connection to https://10.103.2.11:13050: ('Connection aborted.', BadStatusLine("''",))
Retrying 1 nodes that failed introspection. Attempt 2 of 3 
Failed to run action [action_ex_id=4937feeb-6dcd-23df-bc14-a53ca04ce02e, action_cls='<class 'mistral.actions.action_factory.BaremetalIntrospectionAction'>', attributes='{u'client_method_name': u'introspect'}', params='{u'uuid': u'999329ab-0303-4b7c-b4e4-ce3e9af39dcb'}']
 BaremetalIntrospectionAction.introspect failed: Unable to establish connection to https://10.103.2.11:13050: ('Connection aborted.', BadStatusLine("''",))
Retrying 1 nodes that failed introspection. Attempt 3 of 3 
Failed to run action [action_ex_id=11c79b5c-849b-df45-888e-ff4485fe5b7a, action_cls='<class 'mistral.actions.action_factory.BaremetalIntrospectionAction'>', attributes='{u'client_method_name': u'introspect'}', params='{u'uuid': u'999329ab-dfer-4b7c-b4e4-ce3e9af39dcb'}']
 BaremetalIntrospectionAction.introspect failed: Unable to establish connection to https://10.103.2.11:13050: ('Connection aborted.', BadStatusLine("''",))
Retry limit reached with 1 nodes still failing introspection