Air Carrier Dispatcher reported unsecured DG freight on taxing aircraft. Aircraft was summons to return to gate where the unsecured DG issue was resolved.

Narrative

At XA:20 local time I received a message asking 'did load planning call you' - I had not received any call or message from load planning. Nor any message about flight at all. Approximately 30 seconds after the initial communicator message; Dispatch captured an ACARS from load planning: PLEASE; FLT NEEDS TO.GO BACK TO THE GATE DUE TO UNSECURED. DG FREIGHT. THANKS;This was the first and only notification of any issues barring the message. The flight was still taxiing; 10 minutes into the planned 16 minute taxi; returned to the gate; and the unsecured DG was resolved without incident - and without them opening the main cabin door. Load planning did not communicate further with the crew; and never communicated with myself. I confirmed with the crew that the DG issue was resolved at 34 minutes past the hour; and no other communications took place.Load planning bypassed my operational control and directed a flight to return to block 10 minutes into their 16 minute taxi - over half way through the allotted time. Once an issue is noted; Dispatch should be the first point of contact to then determine the best course of action to notify the crew and prevent any regulatory issues. While load planning was correct in that the aircraft had to return to the gate to sort out the DG; they had no way of knowing whether the flight was in a critical stage. They also offered no explanation to Dispatch or the crew regarding the issue. I have attached an image of the ACARS history in Dispatch Tool for Aircraft X.