this is what i mean, it was not Nitro test, i was wrong it was same tweaktester as you used now, but this time you have this results....
MSS requested: 1460
Max packet sent (MTU): 1500
Max packet recd (MTU): 1500
so, you have been using the wrong MTU....
do like this..
open cablenut adjuster, click delete cablenut tweaks and click save to registry
now all fields suppose to be blank
reboot your pc and make a new tweaktest and post result URL
VanBuren