I was referred to this forum with my problem. Installation and connection of Octoprint (Version 1.3.6) to Anycubic I3 Mega (Version 3, 8bit Board, frimware 1.1.0) worked w/o problems. Also uploading of gcode files and start printing is ok. After a while (> 20 minutes) the temperature of extruder and bed drops suddenly. Console just shows that cold extrusion was prevented, but I guess this is just a reaction to the temperature drop. I never had such problems while printing from SD. With octoprint all attempts failed for the same reason. I have no idea what triggers the printer to reduce both temperatures.
I haven't found a similar issue in the issue list yet. Any idea or even advice how to solve this issue? As the printer works perfectly in stand-alone mode I do not see the problem related with the hardware. For me it seems something in Octoprint forces the printer lower the temparature.
Thanks in advance, Thomas