I have used Canvas in my school for the previous two years as a teacher and had great success with integrating Google Drive files. HOWEVER, as my district has made the change to Virtual Learning and Face to Face I've noticed some issues. Some, not all, students aren't able to access the files and are given the "access denied" message.
The issue isn't specific to any student or classroom. It occurs sporadically. I make sure that the students are signed into gmail, drive, and have authorized the drive component of Canvas. I also have ensured that the permissions of the documents are available to anyone with the link. I am in my first year as an Instructional Technologist and feel like I am helpless with this issue.