The OnePlus 3 was having a few auto-restart problems and call quality discrepancies which are being fixed with the latest Oxygen OS update. The update brings the Oxygen OS version up to 3.2.4, so it’s only a minor “hotfix patch”.
If you are updating the OnePlus 3 from the latest public release, it should only a 26MB OTA update. The update is rolling out in stages so you might not receive the notification right away.
The changelog mentions “various fixes and carrier optimizations” as well. Have any of you been experiencing these kinds of problems on your OnePlus 3