iPhone 12 Bluetooth connected, shows it's playing, but no sound

My iPhone 12 is using Bluetooth to stream to two different portable speakers, but I hear sound on neither one. However, if I stream to Google Home or Echo Dot, music plays just fine. While playing, the little equalizer bar is bouncing up and down, showing there is music, and the pause button and length bar also show, but nothing comes out the speaker.

If it was just one speaker, I'd think that was the problem. But it's not working on two DIFFERENT speakers, by two different manufacturers. And both were working an hour ago!

I've tried all the tricks - toggling Bluetooth on and off, force reboot, toggling Airplane Mode on/off, forgetting both devices. I've tried multiple music streaming services too. They'll stream to Echo or Home, but not speakers. Yet it shows the equalizer button and pause button like it would when it was playing.

What now?