Resources/Agent Clusters View reverts to "... folder is empty" message when being updated

Current Situation

When a folder in the Resources / Agent tree is clicked the information about the Agent Clusters configured in that folder will be shown correctly for around 10 seconds. After this time (and coincident with the next agent_clusters POST response) the information shown will change to something like "simple_order_job_agent" folder is empty
The responses to the agent_clusters POST remain correct - eg:

{
	"agentClusters": [{
		"_type": "SINGLE_AGENT",
		"agents": [{
			"host": "",
			"os": {
				"architecture": "amd64",
				"distribution": "Ubuntu 16.04.3 LTS",
				"name": "Linux"
			},
			"startedAt": "2018-02-05T11:22:45.002Z",
			"state": {
				"_text": "RUNNING",
				"severity": 0
			},
			"surveyDate": "2018-02-06T15:24:50.624Z",
			"url": "http://localhost:4441",
			"version": "1.12.0"
		}],
		"maxProcesses": 1,
		"numOfAgents": {
			"any": 1,
			"running": 1
		},
		"numOfProcesses": 0,
		"path": "/test/simple_order_job_agent/agent_4441",
		"processes": [],
		"state": {
			"_text": "ALL_AGENTS_ARE_RUNNING",
			"severity": 0
		},
		"surveyDate": "2018-02-06T15:24:50.611Z"
	}],
	"deliveryDate": "2018-02-06T15:24:50.657Z"
}

The correct Agent Cluster information can be retrieved by clicking on the navigation tree folder link again, where it will be shown for a further 10 seconds.
This behaviour applies to Firefox but not to MS Edge.

Desired Behaviour

The Information shown in the Resources / Agent Cluster view should be correctly updated from the agent_clusters POST message.