If it helps, this issue is being discussed at length here: https://community.canvaslms.com/thread/46875-uploaded-images-no-longer-function-in-safari 

Thanks for the info Suzanne.I'm a student not a teacher so presumably they uploaded those particular images before the 'cut off' date. It also means I can't re-upload and re-insert, but I can make do ...

I am having this issue (with latest version of Mac OS and Safari) and unchecking "Prevent cross-site tracking" doesn't fix it, even with cache and history cleared, and browser closed and opened again....

Thanks for the info Suzanne.I'm a student not a teacher so presumably they uploaded those particular images before the 'cut off' date. It also means I can't re-upload and re-insert, but I can make do ...

If it helps, this issue is being discussed at length here: https://community.canvaslms.com/thread/46875-uploaded-images-no-longer-function-in-safari 

I am having this issue (with latest version of Mac OS and Safari) and unchecking "Prevent cross-site tracking" doesn't fix it, even with cache and history cleared, and browser closed and opened again....