So I powered my printer, connected the Pi and again the webcam stops working when the connection is estblished.
Here are the logs :
2019-11-20 16:14:23,169 - octoprint.server.util.sockjs - INFO - User user logged in on the socket from client ::ffff:10.8.0.3
2019-11-20 16:15:07,495 - octoprint.util.comm - INFO - Changing monitoring state from "Offline" to "Detecting serial port"
2019-11-20 16:15:07,548 - octoprint.util.comm - INFO - Changing monitoring state from "Detecting serial port" to "Opening serial port"
2019-11-20 16:15:07,551 - octoprint.util.comm - INFO - Changing monitoring state from "Opening serial port" to "Detecting baudrate"
2019-11-20 16:15:08,560 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:20,587 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:21,594 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:22,601 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:23,604 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:24,616 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:24,628 - octoprint.util.comm - INFO - Changing monitoring state from "Detecting baudrate" to "Operational"
2019-11-20 16:15:24,634 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:24,656 - octoprint.util.comm - INFO - Printer reports firmware name "Marlin 1.1.9 (Github)"
2019-11-20 16:15:24,665 - octoprint.util.comm - INFO - Firmware states that it supports temperature autoreporting
2019-11-20 16:15:41,415 - octoprint.util.comm - INFO - Changing monitoring state from "Operational" to "Offline"
2019-11-20 16:15:44,606 - octoprint.util.comm - INFO - Changing monitoring state from "Offline" to "Opening serial port"
2019-11-20 16:15:44,611 - octoprint.util.comm - INFO - Changing monitoring state from "Opening serial port" to "Connecting"
2019-11-20 16:15:44,620 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:44,623 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:44,632 - octoprint.util.comm - INFO - Changing monitoring state from "Connecting" to "Operational"
2019-11-20 16:15:44,635 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:15:44,650 - octoprint.util.comm - INFO - Printer reports firmware name "Marlin 1.1.9 (Github)"
2019-11-20 16:15:44,654 - octoprint.util.comm - INFO - Firmware states that it supports temperature autoreporting
2019-11-20 16:17:45,975 - octoprint.filemanager.analysis - INFO - Starting analysis of local:Pi_Zero_Arm.gcode
2019-11-20 16:17:45,980 - octoprint.filemanager.analysis - INFO - Invoking analysis command: /home/pi/oprint/bin/python2 -m octoprint analysis gcode --speed-x=6000 --speed-y=6000 --max-t=10 --throttle=0.0 --throttle-lines=100 /home/pi/.octoprint/uploads/Pi_Zero_Arm.gcode
2019-11-20 16:17:50,104 - octoprint.printer.standard.job - INFO - Print job selected - origin: local, path: Pi_Zero_Arm.gcode, owner: user, user: user
2019-11-20 16:17:50,112 - octoprint.util.comm - INFO - Changing monitoring state from "Operational" to "Starting"
2019-11-20 16:17:50,116 - octoprint.printer.standard.job - INFO - Print job started - origin: local, path: Pi_Zero_Arm.gcode, owner: user, user: user
2019-11-20 16:17:50,122 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2019-11-20 16:17:50,127 - octoprint.util.comm - INFO - Changing monitoring state from "Starting" to "Printing"
2019-11-20 16:17:52,168 - octoprint.util.comm - INFO - Printer seems to support the busy protocol, will adjust timeouts and set busy interval accordingly
2019-11-20 16:18:20,755 - octoprint.util.comm - INFO - Telling the printer to set the busy interval to our "communicationBusy" timeout - 1s = 2s
2019-11-20 16:22:19,952 - octoprint.server.heartbeat - INFO - Server heartbeat <3
2019-11-20 16:26:21,008 - octoprint.server.util.flask - INFO - Passively logging in user user from ::ffff:10.8.0.3
2019-11-20 16:26:21,881 - octoprint.server.util.sockjs - INFO - New connection from client: ::ffff:10.8.0.3
2019-11-20 16:26:21,999 - octoprint.server.util.flask - INFO - Passively logging in user user from ::ffff:10.8.0.3
2019-11-20 16:26:22,663 - octoprint.plugins.webcamstreamer - INFO - Checking stream status.
2019-11-20 16:26:22,675 - octoprint.plugins.webcamstreamer - INFO - stream is inactive
2019-11-20 16:26:23,050 - octoprint.server.util.sockjs - INFO - User user logged in on the socket from client ::ffff:10.8.0.3
2019-11-20 16:26:36,848 - octoprint.plugins.errortracking - INFO - Initialized error tracking
2019-11-20 16:26:49,350 - octoprint.server.util.sockjs - INFO - New connection from client: ::ffff:10.8.0.3
2019-11-20 16:26:49,451 - octoprint.server.util.flask - INFO - Passively logging in user user from ::ffff:10.8.0.3
2019-11-20 16:26:49,491 - octoprint.server.util.sockjs - INFO - User user logged in on the socket from client ::ffff:10.8.0.3