Didn't see Phoenix specifically (bit far from Cornwall, that) but this is making me dig out my notes because we had something weirdly similar over the coast here about three weeks back. Three amber-ish lights in a loose triangle formation, completely stationary for maybe four minutes, then just... gone. No fade, no movement. Gone.
My question is - was yours stationary or drifting? That feels like the key variable nobody ever nails down properly in these reports.
I had my Zoom H5 running for an EVP session nearby at the time and didn't catch anything anomalous on audio, which I know isn't directly relevant but I always note it anyway. What I didn't have was a decent camera on me, which is infuriating in retrospect.
Also curious:
What was the approximate altitude? High enough to rule out drones?, Any aircraft in the area before or after?, Did the triangle maintain its shape or did the lights shift position relative to each other?
The Phoenix area has such a documented history with this stuff (the '97 lights obviously) that I genuinely wonder if there's something about that region specifically, or if people there are just more primed to notice and report. Probably both honestly.
Has anyone cross-referenced Tuesday's sighting against FlightAware or Flightradar24? That's usually my first port of call before jumping to conclusions, even if the results are boring.