Volume drops (auto-ducking) on iPhone 12 mini with iOS 18.3.2

I'm listening to podcasts, music, watching video....and suddenly the volume drops to where dialogue or lyrics are indistinguishable. I have to quit apps and reopen them to get volume back to normal, because pushing up volume controls starts with the new low volume and increasing to max volume brings it up to a higher but still-low volume. As I wrote before:

It happens with different video or podcast apps, iPad & iPhone (was happening well before iOS 18.2.1 that I was on when I previously asked the question, still happening on iOS 18.3.2), sound output through device speakers or airpods. My apps are all set to auto update, so it's not one out-of-date app having conflicts with the iOS.

Nothing is set to be 'listening' or 'speaking': Siri is not enabled, happens when Maps is closed.

I am sure of at least 3 distinct triggers:

One is the Stelo app, when I inadvertently tilt the device from portrait to landscape mode with Stelo open to the glucose graphic screen. (I have not given Stelo permission to give me any notifications so there is zero sound output expected from it). Not that Stelo is not loaded on iPad, so it's not the sole trigger of these problems.

One is MyCap app, which drops the volume even though there is no place to use microphone to dictate text (again, only loaded on phone).

Another is outside noises, like dishwasher starting up when I am watching video on the pad while doing dishes.

Sometimes the volume comes back up when I close an app (Stelo is monitoring blood sugar only when open, so closing it while listening to things is not a viable solution); sometimes I have to quit the podcast or music or video or browser app and reopen it to reset the volume to normal levels.

I think this is iOS preparing to listen for commands, and I am not using Siri or otherwise speaking commands to my iOS or the majority of my apps. Siri remains off for work-related security reasons.

After my previous post, I tried this suggestion without success

Start by going to Settings/FaceID & Passcode, and turning off Attention Aware features.

What else can I do/check/adjust to prevent this?

when I suddenly can't hear and I've got soapy or muddy or otherwise very busy hands.

[Edited by Moderator]