Why does own hosting take a long time to open sites?

Question

Nginx

Good afternoon, there is: a white ip-address, port forwarding to the nginx server on mikrotik, windows server 2012 R2, an nginx server with a website has been raised in Hyper-V. The problem is that a new user who opens the site takes 30+ seconds to load, which is of course a terribly long time. Locally it opens instantly. I'm assuming that the problem is in Mikrotik or in the nginx server. I can send the data of everything that is required
PS I open it locally and remotely with clearing the cache, of course, to check the "first" launch.

Answer 1

It turns out that the site is published on both providers, and it will only be released to the world through the first provider.
An entry for the site in the site's DNS on both IPs? - if yes, then you have asymmetric routing. To check, remove the IP of the second provider from the DNS record.
You can publish a site on two IPs, but for this IP you need to create a separate routing table so that the responses to the client are returned from the IP to which he made the request.

Answer 2

If the problem was with Nginx, then it would take a long time to open locally. Probably the problem is that the provider's channel is asymmetric, the speed of outgoing traffic is low.

Answer 3

You press F12 in the browser, the networks tab, you need to click on the circle / reload to start the analytics, it will reload the site and show in detail which element takes how long and in what order to load with millisecond accuracy
Guessing what exactly slows down is meaningless.
30 seconds it looks like a timeout for accessing some resource, so determine what is not available.