Why no Buy Box? I sell my own product

I have a single product under my own brand. I make it and sell it FBM. I ship from my home straight to the customer. I’ve sold a few on Amazon already. My best store is Etsy, and 2nd is my own website. No sales in my tik store.

So why no friggin buy box?? I also have a message across the top on the browser saying “This product often out of stock”. wtf. It has never been out of stock and no customers have been denied. My inventory is 31. On the app it says “Consider these alternatives”.

Any tips appreciated. thanks