The version of Curl used in the containers of that version isn’t able to correctly validate the certificate for that feed because it contains an expired certificate.
There’s three ways to fix it.
First option is to upgrade to the latest Xibo CMS containers which have this fixed already. That would be 2.3.13.
Second option is to remove the offending certificate from your local trust store. To do so, from the folder where your docker-compose.yml files are: