In my testing machine.lightsleep and machine.deepsleep still don't work (with V1.19 firmware).

The Pico was powered from a bench supply with 5V on vsys. There was no connection to the USB port. main.py was as follows:

import time
time.sleep(5)
import machine
machine.lightsleep(10_000)

Current consumption was ~21mA with a tiny glitch visible after 5s but no change otherwise. The same was true with deepsleep (which seems to call lightsleep).