Welcome to the community @rodascu
Your system is rejecting the Let's Encrypt HTTP challenge with an error that says:
Comportamiento sospechoso detectado
(google translator says: Suspicious behavior detected)
This was the challenge sent by LE to your server:
http://www.rsoluciones.nat.cu/.well-known/acme-challenge/EVMF7_OX92au83kVoJUngfijzkvIQREZfqBZEgOCrYc
You should check your security settings so that you allow these.