Several, and they do not all fail.
4.47:1 is under the 4.5:1 that normal-size text needs, so the links and the small labels fail, and so does white text sitting on that fill — the CTA is text on a colour, and it is judged as text. But the button's own edge against the page is a non-text boundary and only needs 3:1, which your indigo clears comfortably. Large display text has a lower bar too.
So the fix is usually not the brand, it is the rule that the brand colour is not allowed to carry a glyph. Darken one step on the same ramp for anything with text on or in it — the next tint down is typically somewhere above 6:1 on white, which is not a close call — and keep the original for fills, borders, the focus ring and the chart series where nothing is written.
Visually that is almost invisible: two adjacent tints of the same hue, and one of them only ever appears under letters. It is the version of this that design teams accept, because nobody is being told their colour was wrong.
The CTA is the one that gets missed every time, incidentally. It reads as a brand asset rather than as text, so it never gets measured, and it is the single most-clicked thing on the site.