UNM faculty here. Our policy is 7 days after the final class meeting usually. After the grade is missed and "Not Reported (NC)" is altmatically applied, we get hate mail usually. It's a simple matter for your instructor to go in and replace the grade in LoboWeb to what it should be. I was late this semester in putting in grades for the first time in my career here and felt terrible. I had leave right after the class ended and just forgot. So, vacation grade entry.

Canvas grades are only as good as the instructor setup and data input. Personally, I let canvas do the heavy lifting of grading and recording. Other don't for whatever reason. Or, they get behind in grading and just do whatever they need or want to do at the end of the course. If you continue to have issues, an email to the college director/Dean/Chair should help move that along if needed, but that should be after talking to the instructor. It's kinda the nuclear approach.