Hi @AllenMoorhead,
Are you using the How do I change my default email address in my use... - Instructure Community - 410 guide? That should be current info, and even though it's the student guide, the info really applies to any Canvas user. If those steps do not work, it's possible your school/institution has locked down the ability to change default email for a number of reasons. The institution I work at, for example, does not allow changing the default email from the university assigned one to ensure 3rd party apps work as expected and to have the best security available for default notification emails. You could ask your local Canvas team (usually in the eLearning / IT / Digital Education areas) about this if you'd like.
Hope this info helps!
-Chris
