After cluster upgrade, clusterCompatibility still at old value

./testrunner -i /tmp/upgrade3.ini -p get-cbcollect-info=True -t eventing.eventing_upgrade.EventingUpgrade.test_online_upgrade_with_failover_rebalance_with_eventing,nodes_init=4,dataset=default,groups=simple,skip_cleanup=True,initial_version=5.5.0-2958,doc-per-day=2,upgrade_version=6.0.0-1567

2018-08-2802:30:11,

061- root - ERROR - POST http://172.23.104.91:8091/_p/event/setApplication/?name=test_import_function_2 body:{  

   "depcfg":{  

      "buckets":[  

         {  

            "alias":"dst_bucket",

            "bucket_name":"dst_bucket1"

         }

      ],

      "source_bucket":"src_bucket",

      "metadata_bucket":"metadata"

   },

   "appcode":"function OnUpdate(doc,meta) {\n    var expiry = new Date();\n    expiry.setSeconds(expiry.getSeconds() + 5);\n\n    var context = {docID : meta.id};\n    createTimer(NDtimerCallback,  expiry, meta.id, context);\n}\nfunction NDtimerCallback(context) {\n    dst_bucket[context.docID] = 'from NDtimerCallback';\n}",

   "id":0,

   "settings":{  

      "enable_recursive_mutation":false,

      "app_log_max_files":10,

      "curl_timeout":500,

      "skip_timer_threshold":86400,

      "dcp_stream_boundary":"everything",

      "use_memory_manager":true,

      "persist_interval":5000,

      "sock_batch_size":100,

      "dcp_num_connections":1,

      "enable_snapshot_smr":false,

      "log_level":"TRACE",

      "min_page_items":50,

      "fuzz_offset":0,

      "max_delta_chain_len":200,

      "xattr_doc_timer_entry_prune_threshold":100,

      "worker_feedback_queue_cap":10000,

      "tick_duration":60000,

      "deadline_timeout":3,

      "app_log_max_size":10485760,

      "max_page_items":400,

      "worker_count":3,

      "lss_read_ahead_size":1048576,

      "deployment_status":true,

      "lss_cleaner_threshold":30,

      "description":"",

      "dcp_gen_chan_size":10000,

      "lss_cleaner_max_threshold":70,

      "feedback_batch_size":100,

      "auto_swapper":true,

      "worker_queue_cap":100000,

      "cpp_worker_thread_count":2,

      "cron_timers_per_doc":1000,

      "feedback_read_buffer_size":65536,

      "execution_timeout":1,

      "processing_status":true,

      "cleanup_timers":false,

      "timer_processing_tick_interval":500,

      "breakpad_on":true,

      "lcb_inst_capacity":5,

      "vb_ownership_giveup_routine_count":3,

      "data_chan_size":10000,

      "vb_ownership_takeover_routine_count":3,

      "checkpoint_interval":10000

   },

   "appname":"test_import_function_2"

}

headers:{  

   'Content-type':'application/json',

   'Authorization':'Basic QWRtaW5pc3RyYXRvcjpwYXNzd29yZA==\n'

}error:406reason:unknown{  

   "name":"ERR_CLUSTER_VERSION",

   "code":42,

   "description":"This function syntax is unsupported on current cluster version",

   "attributes":null,

   "runtime_info":{  

      "code":42,

      "info":"Function requires 6.0 but cluster is at 5.5"

   }

}