This behavior is expected. FRP can enforce network encryption more efficiently by setting a limit on the number of clients that are allowed concurrent access. If the maximum number of clients is already working on a folder, new clients ignore these folders. The new clients continue to other folders that are configured to be encrypted by the policy.

When the below corresponding policy options are set, FRP creates temporary lock files within the network share folder. The files are of the form SafeBoot Content Encryption folder policy EnforcerX.lock, where X is an integer number. For example:
 

McAfee Endpoint Encryption Policy Enforcer1.lock
McAfee Endpoint Encryption Policy Enforcer2.lock
.....
McAfee Endpoint Encryption Policy EnforcerX.lock
 

Clients create these files after you apply a policy with the following settings:

• Network encryption - must be enabled.
• Maximum clients allowed to encrypt folders - this value must be specified.