Microsoft has started rolling out a new firmware for its Microsoft Lumia 550. The firmware version number is 01078.00042.16352.50012. There is no changelog available but it mainly focuses on bug fixes and improvements.
The update is supposed to bring Camera Improvements along with WiFi, Bluetooth, Cellular and other stability improvements. Unfortunately the double tap to wake feature is still not available.
Update your device by heading to Update&Security section in the Settings app.