observable memory-store not adding items to data-set

[gerhard presser]

I'm using an observable memory-store. if changes happen on the server-side, I'm using store.notify() to update the queries.

this is working well - but if I perform a new query on the store, the notified items are not part of the result.

This works well for JsonRest?-Stores since the data is always fetched form the server.

It seems the store-implementations are not as interchangeable as one would expect.

[dylan]

Duplicate of #18099