Why is ProcessReceipt acting as if it's not there?

local RE = game.ReplicatedStorage:WaitForChild("Events"):WaitForChild("ChangeSong")
local market = game:GetService("MarketplaceService")
local t = {

}
local defaults = {
632765861;
551147202;
503383351;
344405080;
467369212;
284384502;
283762499;
345686522;
356872097;
511077154;
467369212;
216527173;
313246210;
235855135;
320390608;
221896283;
}
function s(obj,ID)
obj.SoundId = 'rbxassetid://'..ID
obj:Play()
local name = market:GetProductInfo(ID)
RE:FireAllClients(name.Name)
end

local current = 1
local sound = workspace.GlobalMusic or workspace:WaitForChild("GlobalMusic")
s(sound,defaults[current])
sound.Ended:Connect(function()
    if current == #defaults then
        current = 1
        s(sound,defaults[current])
    else
    current = current + 1
    s(sound,defaults[current])
    end
end)    
RE.OnServerEvent:connect(function(player,s)
    if tonumber(s) then
    market:PromptProductPurchase(player,53811533)
    t[player.Name] = tonumber(s)
    end
end)

function market.ProcessReceipt(info)
    print('yea12312n3k123nkjandkajsdnsakdsadnaskdasdnadksandkandkjasdsa')
    local player = game:GetService("Players"):GetPlayerByUserId(info.PlayerId)
    if player then
        print('player exists')
        local get = t[player.Name]
        if get then
            print('player is in table')
            local isvalid = market:GetProductInfo(tonumber(get))
            if isvalid and isvalid.AssetTypeId == 3 then
                print('SUCCESS!')
            s(sound,get)
            return Enum.ProductPurchaseDecision.PurchaseGranted
            else
                return Enum.ProductPurchaseDecision.NotProcessedYet
            end
        else
            print('nope')
            return Enum.ProductPurchaseDecision.NotProcessedYet
        end
    else
        print('player is not here') 
        return Enum.ProductPurchaseDecision.NotProcessedYet
    end
end

This is a group place (and the place has a developer product with the id 53811533). For some reason, ProcessReceipt seems to be as if it is not there. I brought the developer product ingame (no studio at all) for one robux and there is no print, but when I move the script into a place that i own (no group) and modified the above code (changing the ID), it works. I don't understand why it doesn't print anything at all in the group place, and I'd like to know how to fix this (if possible).