Hi,
I'm a new seller that offers free delivery to Canada. I find that, several times a day, my settings are being changed without my input so that the free delivery goes away. It also changes to say that I shop worldwide, when I do not. Anyone else experiencing this?
That would be because your listings are syncing with your POD partner, and syncing the shipping profiles setup with them, which would be charged shipping and worldwide.
You need to create shipping profiles with the settings you want and apply them to your listings, so that when your POD syncs, it doesn't resync the shipping profiles you don't want to use.