Not going to sleep when lid closed

The Hall sensor is located on the MacBook Air 13" (Mid 2013-2017) I/O Board

To test things you’ll need a small rare earth magnet and a steel paper clip. Some painters tape which you can cut a few pointers can also be useful.

Using the paper clip slide it on the left side of the display along the bezel frame to locate the magnet within the lid. Once you locate it paste your pointer on its placement. Now carefully fold down the lid and again place a marker on the upper case where the lid point falls. This is the location the Hall sensor is located inside. Now, with the system running slide the magnet across the spot your display should turn off as you pass the sensor. If not then you’ll need to replace the I/O board and you may need to replace the MacBook Air 13" (Mid 2013-2017) I/O Board Cable as well following this guide MacBook Air 13" Early 2015 I/O Board Replacement