Domain Mapping issue

I have a clean multisite installation based on my EC2 server + RDS db (dedicated IP)

All of my domains are managed in Cloudflare (Without using their CDN only the DNS)

I use Laravel Forge to generate my LEMP stack and Let's Encrypt for my SSL Certificates.

I want to use Domain Mapping plugin, when i want to map a domain there is a problem, it gives a 404 error.

The mapped domain is pointing using an A record. Can this be the issue?