Why does my background keep changing?

I don't know why my background for my profile keeps changing. I use discord links for my bg. https://media.discordapp.net/attachments/1169733890815045693/1205723769864192040/0c7b7bd6de1525cecb762d4f3de34ea1.gif?ex=66799704&is=66784584&hm=3b07cd0b018a1cf2fa48df397694e92f9fb066f126673a9dd5097c668219a1fb&= is what my actual background looks like, otherwise it pops up black. If anyone can help me out that would be great. Here is what my code looks like:

     background-image: url("https://media.discordapp.net/attachments/1169733890815045693/1205723769864192040/0c7b7bd6de1525cecb762d4f3de34ea1.gif?ex=66799704&is=66784584&hm=3b07cd0b018a1cf2fa48df397694e92f9fb066f126673a9dd5097c668219a1fb&=") !important;

     background-color: black !important;

     background-attachment: fixed !important;

     margin: 0;

     padding: 0;