The new signature header to prevent 429 doesn't work for add to cart ajax call

Short description of issue

Need this for qa automation, the new signature header to prevent 429 doesn’t work for add to cart ajax call

Link to Shopify Store

Reproduction steps

Make an ajax call with {
url: ‘https://www.jaanuu.com/cart/add?sections=cart-drawer,cart-icon-bubble’,
method: ‘POST’,

} with signature still gives 429.
Other pages loads fine with the signature headers

Additional info

{
url: ‘https://www.jaanuu.com/cart/add?sections=cart-drawer,cart-icon-bubble’,
method: ‘POST’,
headers: {
‘signature-input’: ‘sig1=(“@authority” “signature-agent”);keyid=“redacted”;tag=“web-bot-auth”;created=1759901300;expires=1767677300’,
‘sec-ch-ua-platform’: ‘“Windows”’,
signature: ‘sig1=:redacted:’,
referer: ‘Helia Slim Notched V-Neck Scrub Top - Royal Blue – Jaanuu’,
‘accept-language’: ‘en-US’,
‘sec-ch-ua’: ‘“HeadlessChrome”;v=“141”, “Not?A_Brand”;v=“8”, “Chromium”;v=“141”’,
‘sec-ch-ua-mobile’: ‘?0’,
‘x-requested-with’: ‘XMLHttpRequest’,
‘user-agent’: ‘Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.7390.37 Safari/537.36’,
accept: ‘application/javascript’,
‘content-type’: ‘multipart/form-data; boundary=----WebKitFormBoundaryQXZCtCPkS5f4DSsu’,
‘signature-agent’: ‘https://shopify.com
},
status: 429
}

What type of topic is this

Bug report