Using 5V of L298N to feed ESP32

[leonardus]

I'm using sketch 'ESP32 Web Server' and Motor Driver L298N to run and change direction at maximum speed a dc motor with my smartphone. Feeding the dc motor via the motor driver with a 9V battery. By placing a jumper a separate 5V battery for feeding the L298N is not necessary. The ESP32 is feeding with a separate 4.5V battery. All is working fine.
However removing the 4.5V battery and feeding the ESP32 also by the 12V connection of the L298N the motor turns a second and stops. Also for the other direction.
Any idea what the problem is?

[ESP_Sprite]

A 9V battery in general has very low current-delivering capabilities because of a fairly high internal resistance. Turning on the motor may pull the power line so low the ESP32 resets.

[rodmcm]

Can you show schematic of how the ESP32 gets supplied. ESP32 are 3.3V. I assume you have regulator inbetween. What is the input range of the requlator. See previous answer