I set up Ubuntu 21.04 and installed a Samsung 2675 FN printer/scanner that was working on other Ubuntu machines.
I installed the approprate Samsung driver, added the printer and it prints fine.
I also recognized the scanner
$ scanimage -L
device `xerox_mfp:libusb:001:006' is a Samsung M267x 287x Series multi-function peripheral
However after scanning three pages I switched from "Single Page" to "All pages from feeder" in simple-scan. After scanning about 80% of the first page, the scanning stopped, the pages were just pulled through and sane "lost" the scanner without any further configuration changes in the system.
scanimage -L
No scanners were identified. If you were expecting something different,
check that the scanner is plugged in, turned on and detected by the
sane-find-scanner tool (if appropriate). Please read the documentation
which came with this software (README, FAQ, manpages).
Here is the output from simple-scan
It worked again after restarting the printer, but this is at best a workaround. Just waking up the printer was not enough, so it does not seem to be related to the energy saving mode. The problem was reproducible; scanning multiple pages from feeder caused this problem again
Scanning "single page" and "multiple from flatbed" work, but the latter has the peculiar behavior that it scans the same page again and again until I manually stop the scanning.
I don't really have an idea what could cause such a behavior and also don't know how to go about and debug this. Did someone encounter a similar problem or has an idea what could be causing such an issue? I would also be quite grateful for hints where the sane logs are, so I could investigate myself.