We introduce a new fix in UPM1912.
The Folders to mirror policy and the Exclusion list policies do not work together. The issue occurs because Profile Management does not support using the Folders to mirror policy along with either the Exclusion list – files nor the Exclusion list – directories policy. [UPM-1708]
Under this background, it means if AppdataLocalPackages is configured as exclusion directory, the folder will not be synchronized even it is a mirror folder.
And we find that the path is in the default exclusion list of UPMPolicyDefaults_all.ini, so mirror cannot work.