If my screen is dark I can see recently opened apps through it, How can i fix this?

Hello, Nick.

Thank you for visiting Apple Support Communities.

I understand that you are experiencing unexpected behavior with your iPhone 5s. Since the device is jailbroken, you will need to restore the device to an unmodified current version of iOS in order to correct any unexpected behavior.

Unauthorized modification of iOS can cause security vulnerabilities, instability, shortened battery life, and other issues

Use iTunes to restore your iPhone, iPad, or iPod to factory settings

Cheers