When reconnecting to a server, any placed masks are reverting to the skeleton texture. When popped, they show the proper mask icon. When replaced, they have the correct texture. After logging out and back in again, they're set back to the skeleton texture. It seems the client may not be reading the object data correctly or completely.

Edit: The effect seems to occur randomly, effecting random masks in the area. Some or all in the loaded chunk may be changed. Attached screenshots: Masks inside my house were unchanged, but the ones outside were. Popped and replaced the same items in the second picture.