Mobile browser behavior different than expected

I have a deployed app that records a user’s voice and plays it back. It works fine when I access it via Chrome and Firefox on Windows desktop. I also tested it with the Chrome inspector’s mobile simulator (device toolbar). However, it does not behave as expected when I access it from my Android Chrome browser (Pixel 2). I am using Python 3.8.12, Streamlit 1.4.0, and streamlit-webrtc 0.34.2.

When I hit START to record, the app doesn’t appear to re-execute and the ‘Running…’ status indicator doesn’t show up. Why is the behavior different?

My app
the repo

Update: This appears to be an intermittent problem; it works fine on other people’s Android phones but not mine.