Updated my Flip 6 on Verizon to UI 7 and since updating the screen will randomly (most of the time) not turn on the screen and unlock. It does appear to be more likely to work when plugged into a charger. The phone is working though as I'm able to answer the phone with my bluetooth connected watch and talk even while the screen is black.
I'd warn against updating but it appears based on search that they've pulled back the update. The flaw is bad enough to feel like the phone is nearly a brick at this point.
We also recommend running the diagnostics in the Members app, under the Support tab. You can also use the Submit Feedback option to report the issue to Samsung.
If these steps do not help, it is recommended to have the phone serviced. You can use the following link to find a list of service centers in the U.S. that can do the repair: http://www.samsung.com/us/support/service/location or by contacting customer support at 1-800-726-7864.
If you purchased a Samsung Premium Care or Care+ membership with your device, this plan does cover repairs not covered in the warranty. You can find more information about this plan here: https://www.samsung.com/us/support/samsung-care-plus/
