G28 looks like a rapid movement command.
The G-Code G28 is used to zero return the tool to its zero position via a reference point at rapid speed.
As referenced here, the G28 looks to say, “I have a rapid movement for you to do Mr. printer/CNC”. In the picture, you can see it move first to one position and then another for object avoidance.
I would assume if you are see the temp change to 140C, it probably running a different set of codes.