Why does my computer keep turning on when I close my computer lid?

Show all power setting :

sudo pmset -g

Disable power-up on lid and ac plug

sudo pmset -a lidwake 0 powernap 0

See: Prevent a Mac laptop from turning on when opening its lid or connecting to power - Apple Support

Prevent a Mac laptop from turning on when opening its lid or connecting to power

A Mac laptop with Apple silicon automatically turns on and starts up when you open its lid or connect it to power. With macOS Sequoia 15 or later, you can change this behavior without affecting your ability to use your keyboard or trackpad to turn on your Mac.

1. Make sure that your Mac laptop with Apple silicon is using macOS Sequoia or later.
2. Open the Terminal app, which is in the Utilities folder of your Applications folder.
3. Type one of these commands in Terminal, then press Return:

• • To prevent startup when opening the lid or connecting to power: sudo nvram BootPreference=%00
  • To prevent startup only when opening the lid: sudo nvram BootPreference=%01
  • To prevent startup only when connecting to power: sudo nvram BootPreference=%02

1. Type your administrator password when prompted (Terminal doesn’t show the password as it's typed), then press Return.

To undo any of the previous commands and reenable automatic startup when opening the lid or connecting to power, enter  sudo nvram -d BootPreference in Terminal.

FWIW, your MacBook Pro is designed to start up when you open the lid, plug in the power, or press a key.

You should just let your mac sleep and don't worry about it.

There is no need to shut down your mac every day.

Since no Mac is designed to start up when closing the lid, it begs the question, how do you know it is starting up?

Sorry, I've never had any Mac do that, laptop or otherwise. Maybe contact Apple Support.