We’d be looking for the value of an x-nf-request-id HTTP response header for such a slow request to try to understand what happens based on our internal logs. I don’t think it is really cold-start related, since most folks don’t use their functions very often and I’ve never seen anyone take so long (plus unless our staff adjusted your function timeout, usually we’ll shut down the connection in 10 seconds unless it has already started sending a response - which would mean it was already solidly “running” :))
You can see what we need here: [Support Guide] Netlify Support asked for the 'x-nf-request-id' header? What is it and how do I find it?