Could you please check that the IP address has been updated properly? You can run dig fbwr.freedombox.rocks on any machine to see the IP address assigned to that domain. Then you can run curl ipinfo.io to retrieve the IP address that has been assigned to you by your ISP. They should both match.
If your ISP gives you a public IP address, then you need to ensure that your home router forwards incoming traffic to FreedomBox. This is typically done by logging into the router, and configuring DMZ ip address as FreedomBox IP address (after making a reservation for that IP address).
If your ISP doesn’t give you a public IP address, you can’t use Dynamic DNS. You need to use one of workaround techniques such as Pagekite or Tor hidden service to reach your FreedomBox from outside.
Could you please confirm with your ISP (or by searching online) which is the case?
Also what is DMS? 