Agco c3000 rtk

In the spring my c3000 started to take a long time to get a rtk fix and following a chat with our rep I had to disable the glonas satellites from the ntrip settings.this makes it far more stable but I feel it loses fix slightly more in tree cover. Last Autumn it worked fine and with planting fast approaching I wondered if anybody else has found a way to get back to the full potential that I know the system can perform?
C3000 screen
AGI 4 type reciever
MF 7726 dvt
year 2017.
current ntrip...

Agco c3000 rtk