UserAgent: Mozilla/5.0 (X11; CrOS x86_64 10452.42.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.79 Safari/537.36
Platform: 10452.42.0 (Official Build) beta-channel candy

Steps to reproduce the problem:
1. Set a locked wallpaper in the admin console
2. Wait until it has sync to the users chromebooks 
3. Remove the locked wallpaper, so the user can choose their own wallpaper

What is the expected behavior?
The users should be able to choose their own wallpaper.

What went wrong?
Some of the useres are still not able to choose their own wallpaper, even if they have locked out and updated their chromebook

Did this work before? No 

Chrome version: 66.0.3359.79  Channel: beta
OS Version: 10452.42.0
Flash Version: 

The settings with locking/releasing the wallpaper hos not been reliable for a year or more.