What is the problem?
I click cancel in Octoprint, the printer physically stops printing and (after some time) Octoprint changes from 'Cancelling' back to 'Operational' however the LCD still shows the printing screen. Pressing the printer knob gives me the usual print in progress menu's with the option to 'Stop Print' which I have to do to enable accessing the full printer controls again.
What did you already try to solve it?
Rebooted everything, Upgraded Marlin firmware from 2.0.5.2 to 2.0.5.3
Logs (octoprint.log, serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support!)
2020-04-05 21:07:21,245 - octoprint.filemanager.analysis - INFO - Starting analysis of local:3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode
2020-04-05 21:07:22,412 - octoprint.filemanager.analysis - INFO - Analysis of entry local:3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode finished, needed 1.16s
2020-04-05 21:07:41,260 - octoprint.printer.standard.job - INFO - Print job selected - origin: local, path: 3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode, owner: admin, user: admin
2020-04-05 21:07:41,269 - octoprint.plugins.DisplayLayerProgress - INFO - File '/home/pi/.octoprint/uploads/3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode' selected. Determining number of layers.
2020-04-05 21:07:41,469 - octoprint.util.comm - INFO - Changing monitoring state from "Operational" to "Starting"
2020-04-05 21:07:41,545 - octoprint.printer.standard.job - INFO - Print job started - origin: local, path: 3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode, owner: admin, user: admin
2020-04-05 21:07:41,591 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-04-05 21:07:41,602 - octoprint.util.comm - INFO - Changing monitoring state from "Starting" to "Printing"
2020-04-05 21:07:42,045 - octoprint.plugins.DisplayLayerProgress - INFO - File select-event processing done!'
2020-04-05 21:07:42,057 - octoprint.plugins.dashboard - INFO - File Selected:
2020-04-05 21:07:42,058 - octoprint.plugins.excluderegion - INFO - File selected, resetting internal state
2020-04-05 21:07:42,079 - octoprint.plugins.DisplayLayerProgress - INFO - Printing started. Detailed progress started.{'origin': u'local', 'name': u'XYZCalibration_Cube_[SQ005].gcode', u'user': 'admin', u'owner': 'admin', 'path': u'3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode', 'size': 643485L}
2020-04-05 21:07:42,100 - octoprint.plugins.excluderegion - INFO - Printing started
2020-04-05 21:07:48,360 - octoprint.server.heartbeat - INFO - Server heartbeat <3
2020-04-05 21:08:02,023 - octoprint.util.comm - INFO - Changing monitoring state from "Printing" to "Cancelling"
2020-04-05 21:08:02,038 - octoprint.plugins.excluderegion - INFO - Printing stopped: event=PrintCancelling
2020-04-05 21:08:02,032 - octoprint.util.comm - INFO - Force-sending M108 to the printer
2020-04-05 21:08:02,071 - octoprint.printer.standard.job - INFO - Print job cancelled - origin: local, path: 3.Test_Prints/XYZCalibration_Cube_[SQ005].gcode, owner: admin, user: admin
2020-04-05 21:08:02,084 - octoprint.plugins.DisplayLayerProgress - INFO - Printing stopped. Detailed progress stopped.
2020-04-05 21:08:02,105 - octoprint.plugins.excluderegion - INFO - Printing stopped: event=PrintCancelled
2020-04-05 21:08:02,148 - octoprint.plugins.DisplayLayerProgress - INFO - Printing stopped. Detailed progress stopped.
2020-04-05 21:08:02,160 - octoprint.plugins.excluderegion - INFO - Printing stopped: event=PrintFailed
2020-04-05 21:10:29,567 - octoprint.util.comm - INFO - Changing monitoring state from "Cancelling" to "Operational"
2020-04-05 21:10:29,718 - octoprint.util.comm - INFO - Externally triggered heatup detected
2020-04-05 21:10:41,765 - octoprint.plugins.HeaterTimeout - INFO - Timer Started: 1586117441
Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)
OctoPrint 1.4.0 on Raspberry Pi 3B+
Ender 3 Pro w/ BigTreeTech SKR Mini 1.2 Board
Marlin Firmware 2.0.5.2 / 2.0.5.3
Both Firefox and Chrome as a browser on macOS 10.15.3