Poor LTE performance of iPhone Xs Max

Hello,

I am from India and have an Airtel eSIM in my iPhone Xs Max. I also have a OnePlus 7 Pro on the same Airtel network. I find that under identical conditions the OnePlus achieves 100 Mbps download speeds and the iPhone a measly 30 Mbps. I have tried resetting the network settings on my iPhone and testing it without a phone case. It didn't work, and the OnePlus is 3 X faster. Any ideas? Latest iOS + all App updates installed, 4G VoLTE + VoWiFi on.

Best Regards,

Trinanjan.