What is the problem?
So, recently I installed SKR Mini E3 V1.2 with freshly built Marlin 220.127.116.11 in my Ender 3 and problem started. When I hit Pause print or Stop print from printer LCD, it seems like Octopi ignores it and continues printing. But status on printer LCD actually changes to Print Paused and etc. During Stop my extruder goes to XY home and returns back to the model and continues printing one layer higher. During "Pause" nothing happens, except status on LCD screen.
What did you already try to solve it?
I've tried changing USB cables, changing baud rates. Also I enabled in Marlin FW HOST_ACTION_COMMANDS and HOST_PROMPT_SUPPORT. After that everything the same, but now printer during Stop printer drops down nozzle temperature and print fails because of cold extrusion prevention. Sometimes Octoprint throws print paused or print stopped UI, but nothing actually happens.
The only things I'm seeing are some notification prompts, which are merely prompts, they don't magically instruct OctoPrint to pause just because they contain the word pause. The firmware needs to be modified to send the correct action commands on a pause and resume triggered by the controller.
That's only for showing stuff in OctoPrint and allowing the user to interact. There's neither //action:pause nor //action:paused which would tell OctoPrint to actually pause the print.
Those two things there, prompt and notification, are merely for displaying stuff. There's no actions associated with these commands other than "display something to the user" and in the case of the prompt stuff also "and allow the user to click a button". The firmware can send anything in these messages, that doesn't mean OctoPrint (or any host implementing the prompt or notification protocol for that matter) will have to and actually MUST do anything with it other than display it and in the case of the prompt stuff also spawn some buttons which if pressed then generate an M876 S<button number>.
It's as if someone expected you to answer your door because they rang you once on your mobile but didn't use the actual door bell. Two completely different things.