Officially there is no Win 11 driver; see here:
https://de.canon.ch/support...)

Did you try to re-install the Win10 x64 driver from above download-link ?
Do you mean there's an unrecognized device in device manager ?

There's another solution, you can buy this software, it does support the scanner natively, without need to install a driver.
Check the compatibility list; P-208II is supported. You can try it before purchasing.
https://www.hamrick.com/vuescan...