Help with H-Bridge L298N

Post a schematic. I'm not going to watch a video.

Which video? No one asked you to watch a video.
And how will a schematic help you in this case? Yes schematics can often help (a lot) but in this case it is point less - there is nothing special you need to see.

I said:

I check the output voltage using a multimeter, between the two output terminals.I also tried to connect several loads (for example a motor, and to control its speed) to make sure it is not just false-readings - and the readings are correct.

But just because you asked, here:

  • The battery is either 9V or 11.1V LiPo

The motor's speed matches what I see on the multimeter - analogWrite(1) gives a reading of 5V - and the motor spins accordingly.
I can't get it below 5V (except for 0, off, of course)

Is it better now? If there is anything else you'd like to know about my setup, just ask.
I hope my schematic is good enough.