Took these on my trip to Singapore.
Taken in auto mode with HQ on OnePlus 5T, then touched up in Snapseed.
Had to resize them as the original files...
Ah, thats sad. I'm not using VoLTE myself (i.e not Jio) and my conenction speeds were the same post update .
However if it's really a modem issue...
Inside settings -> About -> SIM status, you can check if its connected to LTE or not. I get the same speeds and same connection, no mattter it says...
4G = LTE . The terms are used interchangeably.
Here is mine, no edits, no crops, no retouching.
You can see more pics taken by me on my FB account
The full size image is here