so, camera worked fine before i upgraded, did the google search but couldn't find anything nor could i find anything on the canon website, yes i know the camera is old but it is all i need for a few ebay pics now and then any help appreciate.....tia
Is your Big Sur updated to the latest? There some USB issues with intermediate updates.
When the camera is connected via USB can you open Image Capture app and see the camera?
If all fails you could get a simple card reader and use that.