Hi Dave,
Removing the first zero makes no sense since all international calls originating in the US and Canada must start with 011. Have you dialed international calls before using the landline? My guess is that your phone plan doesn’t include international calling hence the reason for the call not going through. The dialing sequence is the same regardless of what type of connection is used.
If I am right and your local plan doesn’t let you dial internationally, you can still place the call using the landline with an additional calling service (like a calling card for example). In this case you would be required to dial a local or toll free access number to connect to this third party provider, and then you can dial internationally. Some examples of third party calling providers:
https://www.nobelcom.com/