Start printing after upload

I have two Prusa MK3s printers. Both printers have a separate RPI 3B+ with Octoprint v1.4.2

I am using the PrusaSlicer v2.2.0

If I send a gcode from the slicer to the Octoprint with the command "Start printing after upload", it will be placed under files in the octotrint. Sometimes the octoprint starts to execute the job, but sometimes it also keeps waiting for me to click the Print button in Octoprint.
I can't get a grip on when it starts automatically and when it doesn't.

This is the same with both printers.

This is the Start G-Code in the PrusaSlicer
G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S[first_layer_temperature] ; set extruder temp
M140 S[first_layer_bed_temperature] ; set bed temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
M109 S[first_layer_temperature] ; wait for extruder temp
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G1 Y-3.0 F1000.0 ; go outside print area
G92 E0.0
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line
G92 E0.0
M221 S{if layer_height<0.075}100{else}95{endif}

How can I ensure that the command "start printing after upload" is always executed?

Hello @Satellietje!

Do you have Gcode Editor plugin installed?
Try with this plugin disabled

I have not installed the Gcode Editor

Can you reproduce the same when running OctoPrint in Safe Mode? If you are not able to then there is a conflict with a plugin.

I think you are right.
In Safe mode, 3 prints start directly from the slicer.

Now the challenge is to find which plugin is causing the problem :wink:

Thanks!