Hi @LondonMole,
While the latest 2 versions of Safari (15 and 16 as the time of this post) are listed as supported on Instructure's What are the browser and computer requirements for... - Instructure Community guide, it seems like Safari has the most issues of any browser with Canvas. Part of that may be that Safari is somewhat tied to MacOS updates, so if your computer can't get the latest MacOS version or you've chosen not to install it, you'll probably experience more problems than most others. If you have a new enough Mac to be on the latest MacOS (currently Ventura 13.4), you will likely be okay using Safari for most things, but can still run into issues every now and then with a lot of websites. I'd always recommend having at least one alternate browser (Chrome, Edge, Firefox, etc...) installed so you can switch over to it if you see an issue in Safari just to confirm Safari is the issue and have a workaround available.
Hope this helps a bit!
-Chris