Hi L0pez,
It is expected for the Apple Watch to turn off the display once the Sleep Focus is active as outlined here:
"The Sleep Focus turns off the watch display and turns on Do Not Disturb to reduce distractions before your scheduled bedtime."
If you notice the display is turning off sooner than expected, check your Sleep options under Settings > Sleep on your Apple Watch. By default, the Sleep focus is enabled when Wind Down starts, meaning the display would turn off. You can tweak that under Settings if you'd like.
"Change sleep options
- Open the Settings app
on your Apple Watch. - Tap Sleep, then adjust these settings:
- Turn On at Wind Down: By default, the Sleep Focus begins at the wind down time you set in the Sleep app. If you’d prefer to control the Sleep Focus manually in Control Center, turn this option off.
- Sleep Screen: Your Apple Watch display and iPhone Lock Screen are simplified to reduce distractions.
- Show Time: Show the date and time on your iPhone and Apple Watch while the Sleep Focus is active.
- Turn Sleep Tracking and Charging Reminders on or off.
- When Sleep Tracking is on, your Apple Watch tracks your sleep and adds sleep data to the Health app on your iPhone.
- Turn on Charging Reminders to have your Apple Watch remind you to charge your watch before your wind down time and notify you when your watch is fully charged.
You can also change these sleep options on your iPhone. Open the Apple Watch app on your iPhone, tap My Watch, then tap Sleep."
Let us know if that helps.
Cheers!