Cause: Before creating a file/directory or writing to a file, Quota enforcer requests Quota aggregator for the size of volume to make the decision whether to allow create/write operation. Quota aggregator takes a volume-id and a path and returns the size consumed by that path in the volume represented by volume-id. Because of a string comparison error, sometimes Quota aggregator would pick up a wrong volume and path wouldn't be valid in that volume.
Since path wouldn't be valid in the (wrong) volume picked up by Quota aggregator, query for size of the volume would fail and as a consequence Quota enforcer would fail writes/creates too.
Make Quota aggregator pick correct volume based on the volume-id provided by Quota enforcer.