It worked!!!! Thank you thank you thank you thank you!! You rock, thanks!
Lorenzo

I'll try that, but I'm not optimistic: if that was the problem, it would depend on the power supply, which it doesn't. Thanks!

I have the esp32 devkit board connected to a ws2812b led array, an audio amplifier connected to a dac input io, and a rotary encoder. When I give power (5V) to the circuit the FIRST time, nothing happens. If I remove power and apply it again, everything works properly. All successive times I switch ...