Webcam image scrambled

**Camera model : Logitech HD C310

What is the problem?
Webcam image in Control Tab is corrupt/not showing correct picture (it's in a sort of grey scale and blocky, see attached picture)

What did you already try to solve it?
In Windows the picture is perfect.
Reboot sometimes helps, but that shouldn't be the solution (this time it took me .

Logs (/var/log/webcamd.log, syslog, dmesg, ... no logs, no support)
Sorry, I can't find the logs folder (I'm logged in via SSH user pi, but I can't find the log folder)

pi@octopi:~ ls mjpg-streamer OctoPrint oprint scripts pi@octopi:~ cd OctoPrint
pi@octopi:~/OctoPrint ls README.txt pi@octopi:~/OctoPrint cd
pi@octopi:~ cd oprint pi@octopi:~/oprint ls
bin include lib share
pi@octopi:~/oprint cd bin pi@octopi:~/oprint/bin ls
activate futurize pip3 pyrsa-priv2pub watchmedo
activate.csh markdown_py pip3.7 pyrsa-sign webassets pkginfo pyrsa-verify wheel miniterm.pyc pybabel python
chardetect netaddr pycache python3
easy_install octoprint pyrsa-decrypt python3.7
easy_install-3.7 pasteurize pyrsa-encrypt python-config
flask pip pyrsa-keygen unidecode
pi@octopi:~/oprint/bin cd pi@octopi:~ cd oprint/include
pi@octopi:~/oprint/include ls python3.7m pi@octopi:~/oprint/include cd
pi@octopi:~ cd oprint/lib pi@octopi:~/oprint/lib ls
pi@octopi:~/oprint/lib cd pi@octopi:~ cd oprint/share
pi@octopi:~/oprint/share $ ls

Additional information about your setup (OctoPrint version, OctoPi version, ...)!
OctoPrint 1.5.2 Python 3.7.3 OctoPi 0.18.0
Running on Raspberry Pi 4 2GB (8GB memory card)