In firmware version 1.14.21, we implemented pre-heating with the goal of reducing the time between preparing a print and the print starting. You can read more about it here and there are a few actions that will trigger the printer to pre-heat.
- Interacting with the printer’s touch screen
- Opening the printer’s cover
- Uploading a print to the printer
Is it possible that one of these actions is triggering the pre-heat? It can be a bit challenging to test but allowing the printer to sit idle for a while and then checking the tray temperature immediately after opening the cover should serve as a good experiment .