Airpods Pro 2 noise cancellation worse after firmware update 7A294

The active noise cancellation on (at least) the AirPods Pro 2 is much worse after firmware update 7A294, including 7A302. The noise cancellation effect seems noticeably weaker now, roughly 50-70% as effective. Qualitatively, the effect is now closer to a slightly quieter adaptive mode. Essentially, I can now practically hear everything at a reduced volume, and my Sony 1000XM5 headphones now perform much better than my AirPods Pro 2, and this wasn't the case until the firmware/iOS 18 update.

Troubleshooting steps I've tried:

• Cleaning the AirPods and tips (gentle surfactant/alcohol wipes, Blu-Tack), although they were already clean
• Replacing the tips (they were already pristine)
• Changing tips and ensuring proper fit
• Resetting the AirPods
• Toggling all settings on and off (Off, Transparency, Adaptive, Noise Cancellation)
• Ensuring I hadn't accidentally selected something other than the noise cancellation mode
• Having the AirPods replaced at the Apple Store

None of the above remedied the issue.

Some examples and context:

• I can now fully make out conversations on the train in Tokyo, which I wasn't able to do that up until a day or two ago. To wit, train announcers are now less distant and audible. I can now hear people conversing on the other side of the carriage, and at one point, I was able to make out the music leaking out of someone else’s headphones...
• I can now make out talking heads playing at low volume on a TV in another room.
• I can now make out external sounds when ANC and Background Sounds (Dark Noise) are active at the same time, and up until the most recent update this combination was closer to being fully isolated.
• Background music in convenience stores is now fully present, where as prior to the update I couldn't hear a thing.
• I now no longer bother swapping to Transparency when my girlfriend is trying to talk to me across the room, because I can hear everything she has to say while noise cancellation mode is active. In the past, having to toggle between settings was a source of annoyance for us.

The situation is particularly disappointing, as I once adored these headphones, and the degradation of the noise cancellation effect makes the AirPods Pro 2 essentially more annoying than anything else.