A new firmware update is rolling out to Lumia 550 . The latest Firmware update version is 01078.00042.16352.50012.The update doesn’t bring anything new and changelog is also not there but we can assume that there is bug fixes and stability and quality improvements.
As per the reports, the latest update also doesn’t bring double tap to wake that has been included in earlier firmware updates for the Lumia 650, 950/XL phones.
To check for updates, you can also tap Settings > Update & security > Phone update > Check for updates.
If you notice anything new in this update then please let us know in the comments.