awe

Hi guys, I am playing around a bit to get to know gcode and have generated a gcode file with Cura and then thrown out the xyz control (G0 & G1) I don't need and put my own in instead. The Temperature control and everything else is exactly the same as written by Cura. Now when I print the original gcode my Ultimaker (S3) prints with a constant temperature of 245°. As soon as I print my modified gcode file though the temperature reaches 245 in the beginning (as set using M104 S245), then the printer starts printing and the temperature drops continually until at some point the material is not being liquified enough and I get a "material error". Some work arounds I have tried already: - using M109 -> didn't make a difference - setting the temp back to 245 again and again after different lines of code -> did set the temp but not as I had planned (one try was e.g. T went down to 160 (???) and then back up again to 200, then down to 80 and after finishing the print up to 245 again (wtf??)) Any clues why this might be happening? (Ultimaker & Cura Softwares are up to date; there is no problem with any nozzle connection or else, nor in any cables, or other hardware connections; -> I am pretty sure it lies somewhere in my code, just don't know where) Thanks already in advance for any help! My gcode lines: T0 M82 ;absolute extrusion mode G92 E0 M104 S245 G280 S1 G0 Z20.001 M106 S255 M204 S1000 M205 X20 Y20 G0 X119.785 Y101.634 Z0.4 G1 F50 X119.785 Y101.634 E5 G1 E0 G1 E-25 Z2 G0 X117.785 Y101.634 Z0.4 G1 F50 X117.785 Y101.634 E30 G1 E0 G1 E-25 Z2 M204 S3000 M107 M82 ;absolute extrusion mode M104 S0 M104 T1 S0