adsl2+, adsl2 modulation not working

Right now my modulation is Gdmt. but i want to change it to ADSL2 because people get more speed and good ping on ADSL2 but whenever i changed it my internet light become red.. i have AN102016t router.. few months ago.. i request ptcl to change my line to ONU after they changed ADSL2 never works.. when i was on copper wire it does work.. so now i am getting low speed and high ping then copper wire... and another thing i wonder about is that i still have copper wire in my home.. so they really changed it ? or they make me fool.. the only change i get after ONU is LOW SPEED, HIGH PING.. only Gdmt modulation work now