The screenshot below illustrates 2 issues that you may encounter when checking a Canvas Page for accessibility with Yuja Panorama
Linked files Checked in the Page
One file (labelled #1 in the screenshot above) has been scanned and checked for accessibility by Yuja Panorama. This is indicated by the red accessibility icon next to the file name. Clicking on that icon will open the accessibility report for the file.
The other file (labelled #2) does not display an accessibility icon. The file likely has indeed been scanned, and the instructor likely would see the accessibility icon next to this filename in the Files index page for the course (or the Panorama Course Report). However, it is likely that the instructor may think Panorama has failed to scan the file, or ignore it completely because of the lack of the icon - potentially leaving a major accessibility barrier unexamined.
There is an additional difference between the two files: file #1, when clicked, displays a preview of the file in Canvas. Alternatively, a user can choose to click on the "down arrow" next to the filename to download the file. When the user clicks on file #2, they will be immediately prompted to download. There is no preview. This is also problematic from a user experience perspective.
Why the different behavior? It is because #1 was added to the Page in Canvas, using Canvas's file upload protocols. #2 is a file that was linked to a page in Blackboard, which was then imported into Canvas. A different file upload protocol was used, and the file is not compatible with some of the convenient UI features in Canvas.
The Overall Score of the Page
Note that the overall accessibility score of this page is 89% (considered a "Good" score), even though there is not much on this page at all except for 2 linked files, one of which has a very low score, and the other which has an unknown score. This illustrates that the score of files linked in a page do not "count against" the score of the page they are linked in. Furthermore, the high score of this page does contribute to the overall accessibility score of the course, which is misleading.