Thanks so much for writing. You are right, there seems to be a bunch of stuff that talks about going from Moodle to Canvas, but surely there has to be some way to do the opposite. I have tried exporting the Canvas course and then importing it into Moodle, but it comes in completely empty with only the name of the course.
I don't think there is a way to do the migration process from Moodle to Canvas backward, since they are two completely different platforms with different processes.
If I can't get this solved, I will either have to recreate the entire courses (which requires hours and hours of work) or I will have to continue to use Canvas and not use Moodle, which I hate to do.