Printer keeps overriding my extrusion temp on single nozzle print

I have been trying to print a part for three days now using PETG filament. The part prints fine with PLA but fails every time when I try it in PETG. I have my extrusion temp set to 240C but about 70% of the way through my print it drops to 200C automatically. No matter how many times I manually raise it back to 240 it keeps dropping. I checked every temp in Luban and they are all set correctly. I have no idea what is causing this.

What slicer are you using? If it’s Luban, are you using the PETG presets or are you attempting to modify a PLA preset? Regardless, make sure you select All for Parameter Display in the material settings to see all the parameters, some of which are temps.

I am using Luban. I have tried using the PETG preset, modifying the PLA preset, and I have tried the other profile. On all of these I checked all of the parameters and temps.

How and when are you attempting to set these temperature changes?

I don’t want any temp changes. I have the whole print set to run at 240C except the initial layer which is set to 235C. The printer keeps dropping the temps itself at seemingly random points throughout the print and I have to raise the temp back to 240C on the touch screen every time.

Are you sure it’s the printer doing it? Look at the G-code and find all M104 and M109 commands. Those set the temps.

No you misunderstand me. When you physically key in the override what is the machine doing in the process of the code, is it dropping the temprature to switch working nozzles? Can we see the Gcode? Or is that TS too?