Hello CamilaBelenPC,
Thanks for reaching out to Apple Support Communities. We've reviewed your question and it looks like you’re having an issue with Night Shift on your Mac. It's understandable that you'd want this resolved as that is a very handy feature, so allow us to assist with that. Please start by taking a look here: Use Night Shift on your Mac. Make sure this feature is configured properly. If it’s configured correctly, let’s continue by testing to see when this behavior occurs.
First, put your Mac into safe mode and test. Booting into safe mode will disable any startup and login items from automatically opening, which can help us to isolate the source of the issue further. When you do this, you’ll see some unusual behavior from the display; this is to be expected. Please follow the steps in this article: How to use safe mode on your Mac.
Next, let's see if this behavior persists in a second user account on your Mac. If you have a second account, please log into that and see how it works. If you don't have one you can use, please follow these steps to make a test account that can be deleted later: Set up users, guests, and groups on Mac.
Please let us know how these tests go. We're here for you. Have a fantastic day!
