It would be really good to know your CMS version and if it’s docker or manual/custom installation.
Regarding the feed itself, could go through Report Fault wizard please?
ie enable debugging, recreate issue (force CMS to try and parse the feed), check logs.
If it’s manual/custom installation then please do have a look here Using Tickers, Forecast, Twitter and other external resources that make use of HTTPS connections
If it’s manual/custom 1.8.2 installation, please also make sure that DocumentRoot, URL rewriting, XMR, XTR are correctly configured - https://xibo.org.uk/manual/en/install_environment.html