Vary for Images not working properly

Hello, i enabled vary for images following this guide
https://developers.cloudflare.com/cache/advanced-configuration/vary-for-images/#enable-vary-for-images

This is the result i got from the PATCH API call:

{
    "result": {
        "editable": true,
        "id": "variants",
        "modified_on": "2023-10-30T21:38:20.441437Z",
        "value": {
            "jpeg": [
                "image/webp",
                "image/avif"
            ],
            "jpg": [
                "image/webp",
                "image/avif"
            ],
            "png": [
                "image/webp",
                "image/avif"
            ]
        }
    },
    "success": true,
    "errors": [],
    "messages": []
}

But it doesn’t work properly. It seems that Cloudflare is always just caching the first format that is requested. Are you aware of any issue with this? Thanks