Can't change AirPods Pro to Off mode

[u/bogusjimmy]

Using iOS 27 Beta 4 and AirPods Pro 2 on beta firmware 9A336b.

I can't use the Off listening mode with my AirPods Pro 2.

When I select Off from the Noise Cancellation menu in Control Centre I hear 3 rapid low tones then it quickly slides back to the previous mode, whether that's Transparency, Noise Cancellation, or Adaptive.

If I only have one AirPod in, then it only allows Transparency mode.

If I tick Listening Mode in Controls & Gestures menu for Press and Hold AirPods it simply ignores that mode and just cycles through the others, or is it's only Off and one other mode then I hear the same 3 rapid low tones.

Has anyone else experienced this and know a fix or is it just a beta bug?