a) Latency varies with different mobile phone models
b) Try to play game specifically in gaming mode in mobile phone
c) Internet connectivity should be fine
d) RESET the BT device

1- Remove device name from Bluetooth Interface
2- Open the charging case and let the buds stay in
3- Press and hold the reset button for 7 seconds
4- the LED on the buds will blink 5 times indicating the buds have been RESET then repeat the pairing process. 

e) Restart the Mobile Phone