PWR500

Has anyone seen this before. At first I thought my printer (Ender 5 Plus) had gone mad when the print started but quickly realized it was the slicer file that was the problem. Have redrawn the part a couple of times in F360 to see if it is the .stl export but I get the same result each time. Its a very simple design that should have just a basic grid infill. Cant explain where the extra corner supports come from or the filament path they are formed with (might have to zoom to see it).