It seems like something on vpscloud.biz is set up to auto-respond to HTTP-01 by echoing the provided token, but with a specific account key thumbprint. See, for instance:
curl http://vpscloud.biz/.well-known/acme-challenge/this-is-not-a-challenge
this-is-not-a-challenge.ggSx6hy43AXM901bwJ_Dr4mYLANeJZ8AC4Xxg_N3Bgg
Note: The part after the “.” is supposed to be a thumbprint (aka fingerprint) of an account key. In this case, the “gg…” thumbprint doesn’t match the thumbprint of your account key, as shown in the keyAuthorization part of your logs.
I think the next step would be to figure out what is responsible for answering that query on your server. I would search your Nginx configs for “well-known” to see if there is any special rule catching such URLs.
Is it possible that Vesta is has its own builting Let’s Encrypt integration, and that is interfering with your attempted Certbot runs?