This is true on it’s own. However, you don’t need the DNS record to appear everywhere, you only need them to appear to our CNAME record check, and to the DNS validator of the SSL provider. Both are configured to have much shorter cache, so DNS caching should take at most a few hours, not a few days.
If it takes more than a few hours, it probably means your CNAME record is not correct. And I checked your domain, and it isn’t. Please note that the CNAME host should be _acme-challenge.hypnose.free.nf. Please make sure to NOT include your domain name in the subdomain part so it becomes _acme-challenge.hypnose.free.nf.hypnose.free.nf, because that’s not correct.
Normally, the client area should be able to setup the CNAME record for your automatically, but it doesn’t work because of this issue. Once that issue has fixed itself, you can just click a button from the client area to setup the CNAME record correctly.