I've had the same issue. Happened with my MBPro and my Canon 9000F Mark II scanner all of a sudden, and I hadn't made any changes. I can scan from the utility, but can't scan from My Image Garden and can't save images after scanning from the scanning utility. Also couldn't add scanner back into the printers/systems and preferences. The scanner worked fine for a lomng time, then all of a sudden, didn't. never got it working again. Just got an new Macbook Air M1 2020 and same thing. Frustrating to no end. Yes I have the latest everything from Canon. Yes I have restarted, etc. Yes, I have done everything possible. This is on the Canon side.
What version of OSX is installed on your Mac?
When you attempt to scan using the IJ Scan Utility, does an error appear? If so, what is the exact wording of the error message that you get?