Hello  @Kamil277 

In the right top of Live view page , switch from Day Mode/Night Mode multiple times, will infra leds turn on or  will live feed turns  into black and white color ?

Try to gently shake the camera.

Try a factory reset on camera How to reset my Tapo camera

If the infra led never turn on, or camera will not enter night mode (live view goes into black and white), it could be defective , it is recommended to reach local support or retailer to check device warranty.