Getting low download speed when connected to huawei hg8120c ont

[GR2]

I have connected the fiber wire to this ont, so i can enable bridge mode myself instead of calling airtel customer care. I am on 300 mbps plan and for some reason, i am getting 60 mbps download. upload is normal. It's the same on route and bridge mode. The dl and ul is normal on airtel's own ont (Nokia) though. Any solution?.