Why is my domain still not approved after 48 hours?

Usually one of three documented causes: the domain was added without the required www prefix, a CAA record is blocking SSL issuance, or your host could not add one of the two CNAME records because it conflicted with an existing one. But check the clock first: propagation takes up to 48 hours and approval up to 24 hours after that, so 48 hours may be too early to call it a fault at all.

Why systeme.io still shows a domain as not approved

The clock systeme.io itself gives you

The two waits stack, and that is the part worth getting straight before you go looking for a fault. systeme.io says DNS records take between 24 and 48 hours to fully propagate. Then, provided the domain is functional and properly configured, it says the domain will be approved within 24 hours of that.

So 48 hours is not the deadline. On systeme.io's own figures the wait can legitimately run to about 72 hours, and a domain sitting unapproved at the 48 hour mark may be a domain whose approval clock has only just started.

Past 72 hours with nothing changing, the delay is not propagation. Something in the setup is.

Cause one: the domain was added without www

systeme.io requires the domain to be added with the www prefix, for example www.yourdomain.com. Adding the bare root domain instead, without www, is stated directly as a configuration that will not be approved at all, not one that only takes longer to clear.

Cause two: a CAA record blocking the SSL certificate

Connecting a root domain can fail with an explicit CAA error, meaning systeme.io could not issue an SSL certificate because of a CAA record already on the domain's DNS. This shows as a named error rather than a domain that sits pending indefinitely, so it is easier to notice than the other two causes here. systeme.io's fix is to remove the domain from Custom Domains first, add eight specific CAA records authorizing Amazon's certificate authorities, then reconnect it.

Cause three: a CNAME your host silently would not add

Two CNAME records have to be created in the domain's DNS zone. systeme.io's own connection guide says a host can sometimes fail to record one of them because it conflicts with an existing DNS entry, and the fix it gives is to contact your hosting provider, name the conflicting record, and ask whether it is safe to remove. Unlike the CAA case, this failure does not show as an error inside systeme.io. The record only looks like it was never added.

How to check which one it is

systeme.io points at a DNS checker for confirming the two CNAME records are actually live: paste in the full hostname systeme.io shows under its domain settings, including your domain, and check the CNAME option. Both records need to show green before approval can happen at all. If they are missing rather than merely slow to spread, a conflicting record at your host is the likely reason, and that is a question for your host's support rather than systeme.io's.