isubhambapna, May 24, 2019 : Except for the OnePlus 5T, I've used all the OnePlus devices till date. But after using their devices for a few years, I've realized that there's a serious issue with the network mode on all the OnePlus devices. How I tested? I have 2 Jio SIM cards, 2 Idea and 2 Airtel. Using a Xiaomi Redmi 4, Samsung Galaxy S8 and OnePlus 6T. First I uses Airtel in Redmi 4 and Samsung Galaxy S8 - there was no movement from 4G to 3G or 2G. I then shifted the SIM to OnePlus 6T so now there was one Airtel sim in Redmi 4 and one in OnePlus 6T. The speed was good at the beginning, suddenly the network shifted to 3G, I had to turn on Airplane mode and turn it off to get back 4G. I repeated the above process with all the SIM cards, The S8 and Redmi 4 didn't at all shift from 4G to 3G and provided good data speeds. But on the OnePlus 6T, I did get good speeds, but the network would randomly switch from 4G to 3G. I also tested the same on OnePlus 5 and there was a fluctuation in it too. I think the company has some issues with networking on the devices, it should be solved soon. Also, Android has a code which I can use and make network mode as 4G, but that's not something I'd want to do again and again, so I never tried. I didn't find this issue at places where network coverage was good, but at places where there were network isn't that strong, the Redmi 4 and S8 provided stable network and remained on 4G while the OnePlus had too many network fluctuations and kept switching to 3G Additional details: 1. All the devices were fully charged. 2. All the devices were on the same table. 3. At the time of testing, the devices had only single sim active - slot 1. 4. The SIMs didn't have any issues and were working fine on the other two devices.