apple watch speaker not working

My Series 3 Apple Watch suddenly has no sound whatsoever! Silent mode is OFF. Do-not-disturb is OFF. Volume in the Sound and Haptics setting screen is all the way up. Still no sounds. I noticed it last night when I put it on the charger (it usually beeps when starting to charge) and this morning when I exercised (no beeps on countdown or when timer went off to notify me to go to next station).

How do I turn sounds back on?