First there is the noise generated internally by the microphone itself and its built-in preamp (called "self-noise" in the specs). On top of that you've got noise from your mic pre due to the large amount of amplification needed by a ribbon mic, probably exacerbated by a too-low input impedance.
Both factors conspire to make ribbons inherently noisier than condensers, kind of a dirty little secret that isn't talked about much. Maybe it's why ribbons are often recommended for loud sources such as brass instruments and guitar cabs, where the SNR isn't going to be an issue. When you see ribbons used in pro studios on vocals, they're typically expensive microphones - you're unlikely to see a Fathead or an Apex outside of bedroom studios.
AEA addresses the noise problem by offering their own preamps to go with their ribbon mics, amplifiers with extremely low noise, high gain and appropriate impedance. They also cost as much as most of the microphones themselves! But you're going into a general-purpose mic pre that wasn't designed with ribbon mics in mind. I suspect any prosumer interface is going to be a little disappointing. I know my own (MOTU) interface isn't well-suited for ribbons, requiring the gain to be near its maximum setting.
Many ribbon manufacturers don't even publish self-noise specs, probably because they'd be too embarrassing. I checked, and the spec for your mic is published: 18dB (A), which puts it in the middle of the pack for self-noise among ribbons (but would be considered a little on the noisy side if it was a condenser).
The trick is attempting to measure the mic's self-noise yourself and comparing it to the published spec so you can determine if it's defective. I've never tried this myself, but I imagine making a recording with and without the mic plugged in should reveal how much noise the microphone is generating. The room would have to be very quiet, and you might need to put some acoustical absorption around the mic to eliminate environmental noise such as computer fans and distant traffic.