Hi David,

In COMMAND mode for “Snapshot” it is intended the current state of the entire list, consisting of a set of itemEvents, one for each “key”.
Note that the snapshot is not a playback of the commands received so far.

So, it is the normal behaviour that you receive a "ADD" command with the last data values for each keys present in the Item at the moment of the snapshot request.

Anyway in COMMAND mode you must always consider that data values are ​​sent with the "ADD" commands. Whatever the implementation of your adapter
this can happen both in phase of snapshot request and in cases where the servrer must match multiple updates (an ADD with a subsequent UPDATE merged due to frequency or bandwidth limits for example).

Hope that help.