Have you updated your OnePlus 3 to Oxygen OS 3.2.7?
OnePlus had started rolling out Oxygen OS 3.2.7 update for the OnePlus 3 last week and it should be available on most units by now. We have already installed the update on our unit and the phone has been performing as well as it has always been.
The OTA update weighs in at just 6.7 MB but it does improve gameplay performance for some games and also fixes ringtone issues with the Alert Slider which we never faced. If you haven't received the update yet, just wait a little while more.
Although we haven't faced any issues with the recent built of OxygenOS for the OnePlus 3, some users have complained that the after the 3.2.7 update their battery life has taken a toss. However, this has been reported by a very small percentage of users, so it's not something to worry about. If you are concerned though, just hold off on the update for a little while longer.