Venu 3 HR Sensor Stops Working

I recently purchased a Venu 3 a few days ago. Starting today (9/6/2024), I noticed the HR sensor stopped working - LED lights weren’t on. After restarting the watch, this seemed to fix it, but only for a few minutes. 

Is this a power saving feature? Battery was around 40% when I noticed this happening

Is this a bug with the latest SW update (11.14)?

Is it something else?