01-28-2021 12:28 PM - edited 01-28-2021 12:32 PM
I had this printer for years now. Needless to say, I had the exact same problem. Printer over WiFi works fine, but when you try to scan, sometimes work, most times wont.
I tried everything, reseting drivers, diferent computers, conected the printer near my WiFi router, disable ports, firewall, nothing woked... (conection over USB cable works but I have no space near PC).
So I check youtube and found a guy with the same problem. He did not fix it but found a way around it.
Basically, download another scan software!!! THATS IT
GO to windows store and search for 'Windows Scan" Is free and it works all the time!! So this is most likely a bug in the canon software.
The only down side I can see is that it doesnt scan to PDF. But if this works I would guess any third party scan utility should work.
This is the link for the video.
Hope it helps!