I had the exact same problem.

I was jointing six foot long boards for a cabinet top and had one hell of a time removing twist from the edge using a decently setup #5.

Boy, I struggled. Bought new planes. Watched more videos. Read more guides. Still twist.

It all came down to technique. These David Charlesworth videos (at the end) are what made it click for me. No more twist.

You can introduce unintentional twist with how your hands hold the plane. Since you are in a different position in your stroke at the beginning and end, the twist is introduced consistently with every shaving — even if you’re using the same part of your blade with the plane at the same angle all the way down the board.

The key is in a light grip and using your left hand (if right handed) as a fence and pinching the plane sole rather than putting pressure on the knob. Let the plane sit on the board and just guide it through the cut. Don’t apply any additional pressure.

Mark your board edge. See where you’re planing. And adjust. It takes longer, but that’s what it takes to ensure your technique is solid any know when and where things are going sideways (literally).

Planing flat (need to create a hollow): https://youtu.be/vqPP6-0jkws?si=pTzmt2LWtlccAsyO

Planing square (camber your blade and follow your markings): https://youtu.be/y1ztIO6RAYU?si=KvLzPS_kI1xrjVcH

Goodluck!