Probable Cause 1

Some Timers have half-wave rectifiers built into their power supply circuits. In this case, only half of the AC voltage will be supplied to Sensors and Sensors will not operate. Therefore it cannot be used to operate Timers.
Countermeasure
Instead of using Proximity Sensors, use Relays such as MY2N-CR General Purpose Relays to switch Timers power supply. (Pay careful attention to the contact capacity.)

Probable Cause 2

The Sensors output may have been damaged due to Timers inrush current when the power was turned ON.
Countermeasure
Instead of using Proximity Sensors, use Relays such as MY2N-CR to switch Timers power supply. (Pay careful attention to the contact capacity.)