What could cause this? Not hot enough hardened steel nozzle?
Using the generic petg profile for both overture and polymaker I get matte finishes with some slight bubbling in areas but what I found is that the main middle seems to print somewhat well while the supports seem to really struggle and fall apart.
Try drying your filament and then calibrate the filament afterwards.
You ca also reduce the speed of the support structure. As I had this problem especilly with the tree support, I had to reduce speed for “Support” to 80mm/s.
Good idea thanks. I am also confused why these two filaments were coming out matte instead of glossy.
Other brands always prints glossy and these two petg brands I have are not marked as matte in color.
Coming out glossy or matte mostly depends on different factors, but mainly two are the important ones: speed and temperature. Try to print a temperature tower to see, how the look depends on the temperature. And try to print a single cube at different speeds to see, how the speed changing the final look. If you have discovered how these two factors change the outcome, you can take of it before printing and you can influence the final look of your print. 
