Durability items getting corrupted during stack/unstack - metadata duplication issue

Having issues with my custom durability system where item metadata gets corrupted when multiple players stack/unstack the same item quickly. The durability values show as negatives in the UI and sometimes items end up with duplicated metadata like {"durability": {"durability": 45}} instead of {"durability": 87}.

MySQL logs show 'Deadlock found when trying to get lock' during peak times and I'm seeing malformed JSON in the database. Using QBCore with custom durability integrated into qb-inventory, oxmysql 2.7.3, and OneSync Infinity.

Here's my current stack event handler:

RegisterServerEvent('qb-inventory:server:StackItems', function(fromSlot, toSlot, amount)
    local src = source
    local Player = QBCore.Functions.GetPlayer(src)
    local fromItem = Player.PlayerData.items[fromSlot]
    local toItem = Player.PlayerData.items[toSlot]
    
    -- Direct database update without transaction protection
    if fromItem.name == toItem.name then
        MySQL.update('UPDATE player_items SET amount = ?, metadata = ? WHERE id = ?', {
            fromItem.amount + toItem.amount,
            json.encode(fromItem.info), -- Vulnerable to concurrent modifications
            toItem.id
        })
    end
end)

Anyone dealt with concurrent metadata updates causing corruption? The inventory sync fails between client/server during these events and it's affecting gameplay heavily.