Hi, I have the same problem with an HP Officejet 7310 AIO:
sane-find-scanner reports: "found USB scanner (vendor=0x03f0 [HP], product=0x4211 [Officejet 7300 series]) at libusb:002:012" but "scanimage -L" fails: "No scanners were identified." Unfortunately, I wasn't able to downgrade to 3.20.3+dfsg0-2. There are (too) many dependencies, and I couldn't find the 3.20.3 packages on the Debian servers). A fix or a workaround would be very much appreciated. Regards and thanks for your efforts, HG