AirPods Pro3 hearing aid: intermittent audio fading

I am using AirPods Pro3 as hearing aid with iPhone 17 Pro, iOS 26.2.1, AirPod firmware 8B34.

All the latest currently available versions.

I am experiencing an issue with one ear or the other intermittently fading out.

It can last a few seconds, or up to a minute or so.

Can happen in either ear, but typically not both at the same time.

Appears to be very random, with no obvious trigger.

In AirPod settings have set 'Conversation Awareness' Off, Adaptive Audio to minimum, Spatial Audio Off.

In Hearing Assistance have set Ambient Noise Reduction to minimum, Conversation Boost Off.

These are all the features I can find that appear to have dynamic adjustments that software is constantly manipulating.

Does anyone have any insight as to why this happens, or if there are other settings I should manipulate?