MK4 stop extruding midprint  

MK4 stop extruding midprint

Hi everyone,
I bought my mk4+mmu3 about 3 months ago and everything worked perfectly until a month ago when the printer stopped extruding mid print and I had to interrupt it. Since then I can't print anymore because the issue occurs in every print, even in the prints that I have successfully completed before. I'm using some Sunlu Pla+ and I'm printing it with a temp of 215°C but the issue is present even with a new spool of Prusament Pla.

Here are the list of the thing that i checked:

• cold pull + cleaned the nozzle with a needle;
• changed the filament from Sunlu Pla+ and tried a new Prusament Pla spool and also a Prusament Petg with their respective profile;
• changed the thermistor and all the hotend;
• checked the Idler screw tension of the extruder and the mmu3;
• checked and recalibrated the extruder planetary gear;
• checked and tested the fan;
• reduced the print speed;
• reduced the temp and also raised it (i cannot complete a temp tower but everything was printing perfecty at 215°C before the issue);
• printed with retraction set to 0;
• checked the room temp that is around 29°C and the heatbreak temp that is around 36-38°C while printing.

I'm struggling to find a solution of the problem. Does anyone ever had such problem?

Link to photo and video of the issue