CloudObject includes double the data that was expected

Questions
,
1

Hello!

I’m simply adding numbers to a list in a CloudObject. But here, double entries are created. Can anybody show me the problem or is it a bug?

obj= CloudDeploy[{},CloudObject[]]; 
func=APIFunction[{"data"->"Number"},(CloudPut[Append[CloudGet[obj],#data],obj];
ListLinePlot[CloudGet[obj]])&,"GIF"]; 
CloudDeploy[func,Permissions->"Public"]

Thanks. Falko