Checkout links doesn't work

Here link to docs about checkout links: https://help.shopify.com/en/manual/products/details/checkout-link

Today I found out that the option for several products has stopped working:

https://my-shop-name.myshopify.com/cart/36485954240671:3,31384149360662:1

I checked it on several stores and everywhere after clicking on the link gives a 404 not found page.

Works only if one product, for example:

https://my-shop-name.myshopify.com/cart/36485954240671:3

I also noticed that earlier the last comma was ignored. And now, if it is, it does not work again. For example, it doesn’t work like this right now:

https://my-shop-name.myshopify.com/cart/36485954240671:3,

It looks like a bug.

The links are working again. It’s interesting to find out what the reason was.

Interestingly enough, Checkout URLs stopped working for us too for like 2 hours earlier today. We use a custom storefront and the Storefront Cart API. I reached out to Shopify support to no avail - they claimed there was no known issue but I am convinced they pushed a broken release and didn’t even bother to update the API status page for some reason.