I’m using a free tool called Sigil1 to fix missing anchor link attributes in an ePub export from Canvas. This issue is probably because the course was created with CidiLabs Design Tools and the export just isn’t made to handle the complexity of an external tool like this.
https://youtu.be/jhcVRrvL7gM
1 If I was stuck doing this myself, I’d likely just use VS Code or some other text editor. Hopefully, I will not be stuck doing this.