Problem L298N not taking PWM for speed control

Hi, ( my first post ever here! )

Pplease help if you can on this! I have Arduino Uno , L298N powered with 4xAA, driving a small DC motor. Common ground. It runs fine with speed control jumpers in place. Removing them and inputing signals to speed control pin from e.g. Port 9 gives nothing (despite having full 5V here). Testing to connect cable from Auduino 3V port to L298N speed pin gives full rotation, but testing the same from Arduino 5V port gives no rotation. I have replaced L298N, same error persists. Why is it that 3V port is ok but not PWM controlled port or 5V port? Br Tomas F.

Those pins are active LOW (0v). See the schematic HERE

More Details HERE

DISCLAIMER: Mentioned stuff from my own shop...