Local and Locallow copying back to server

[clareq]

In some cases i'm seeing uses with very large profiles. Investigation shows that AppData within their profile includes local and LocalLow, which should be excluded from copying with the profile. I've pushed out a registry fragment via GPO which should prevent this:

 

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]
"ExcludeProfileDirs"="AppData\\Local;AppData\\LocalLow;$Recycle.Bin;OneDrive;Work Folders"

 

But it's still happening. We are running Windows 10 LTSB. It's not happening to everyone, but I'm having trouble pinning down anything in common with those affected. Any ideas?