Web Console View not updating for some nodes

I am running (4.1 EE). Unfortunately one of my data nodes is not updating its stats i.e. count of documents/memory etc on the main view page. I can see these getting updated correctly when i click on the server and go into the detailed bucket level analytics page(index.html#sec=analytics&statsHostname=****) Any idea what might be going wrong? see attached snapshot(the data/disk usage is set as N/A)

restarting the data nodes resolved the issues and the stats were getting displayed correctly.