why isn't my remote function returning a bool?

for some reason the server wont return a bool value or maybe the client isn't picking it up, please help. Btw i have left the rest of the code out because it is unnecessary and is hard to read.

Client:

Uis.InputBegan:Connect(function(inputObject)
	if inputObject.KeyCode == Enum.KeyCode.E then
		if mouse.Target ~= nil then	
			part = mouse.Target
			part = part:FindFirstAncestorWhichIsA("Model")
			if part then
				local ig = reqGrab:InvokeServer(part) -- the remote function
				if ig == true then -- the problem
					print(123456)
					isGrabbing = true
				end
			end
		end
	end
end)

Server:

function requestGrab(player, part)
	if playerParts[part] ~= nil then return false end -- will not let code run if part is associated with a player, 
	if collectionService:HasTag(part, tag) then
		local primaryPart = part:FindFirstChild("PrimaryPart")
		if primaryPart then
			playerParts[part] = player
			applyConfig(part)
			for i, v in pairs(part:GetChildren()) do
				v:SetNetworkOwner(player)
			end
			print(part.Name .. " Successfully claimed!")
			return true -- i want this value to be returned to the client side		
		end
	end
end