Go to the BP_PlayerInventoryComponent and create a new function called Clear Holdable and add an input called Play Animation and set its variable type to Bool.

Then copy the images below adding the highlighted nodes.

Part 1
Part 2

Next go to the event graph of the BP_PlayerInventoryComponent and create a new custom event, call it ServerClearHoldable and copy the settings for it from the image below.

Then copy the image below using the new function you created earlier.

You can now use the ServerClearHoldable event to unequip a held item, it will also deselect the quick slot.