Firstly check if the RSS Feed is working in Firefox or Edge.
If it is not then it could be that there is no internet connectivity on the Optymyse server or an issue with the feed source itself.
If the feed is working in Firefox and/or Edge but not Chrome you will need to install a browser extension in Chrome, which can be found here:
Once you have installed the browser extension refresh your display/page and the feed should work. If not, close down Chrome and open it again then reload and refresh the display/page.