Baseband connection erros

Hello all... I've been using the Tyrannus rom for a while now, but in the latest update I've had connection issues with the fact that the Csc and PDA is from a different country. I live in Australia. I still get 3g, and H+ but I don't get 4g anymore... Was wondering if it's even important? But I would like to know if it's possible to change the PDA and Csc to my country/region,

Current baseband: G920FXXU3ZPA

from xda-developers http://ift.tt/2cEqX7u
via IFTTT