Permissions on a table lost when Snapshot job runs at Publisher

We have a weekly snapshot replication job (pull) that creates snapshots every Saturday. The job at the subscriber runs continuously. When this job runs, the permissions given to users on 'ABC' table are lost, and we have to go back and grant the permissions manually every Sunday. The permissions on 'ABC' aren't tampered with in the Publisher. Then why are the permissions dropped on the subscriber when a snapshot is applied? This lack of permissions hampers business critically. Please advice.