This ad not working

I placed ad in post with this code

<div style=”display: flex; flex-direction: column; margin: auto auto 40px; width: 305px; height: 430px; background-color: rgb(237, 237, 237); padding-bottom:53px”><div style=”font-size: 12px; width: 100%; height: 30px; text-align: center; line-height: 30px; z-index: 1; background-color: rgb(237, 237, 237); position: relative;”>Advertisement</div><div style=”position: sticky; top: 2px; margin: 0px auto;”><div style=”border: 0pt none; margin: auto; text-align: center;”>
<div style=”max-width: 300px; max-height:200px; box-sizing: border”></div>
</div></div></div>

Ad is showing this correct styling but stickying on top effect not working as I tested on code editor, see video : https://drive.google.com/file/d/1I3czq4cxxvtsNvplObo1WBVzLFXqeAIl/view?usp=drivesdk

• This topic was modified 3 years by Shubham Patel.