It hasn't worked right for weeks. There was an ebay tech post weeks back that they were "aware" of it but of course, no fix even weeks later. Sad that ebay doesn't care enough to fix this.
Someone else posted this manual work-around:
Go to the listing description (either when you create it or in edit mode), click on the "HTML" view and then copy/paste this code into the first line of your description: <meta name="viewport" content="width=device-width, initial-scale=1">
That's all eBay is doing when you click "Fix This for Me" when the code is missing, anyway.
Create/edit your listing as per normal and click "List/Save/Whatever" at the bottom of your screen as you usually do when you're done.
The above coding won't be visible on the screen when people look at your listing but it will correct the "viewport missing" error and make your listing "mobile friendly."
