As Sharkbite & Neil said, you may have gone off the end of the stone and hit the belly of the blade. Just one stroke would cause this. The other side, left looks like the stabilizer may have caused the scratching on the Duck, I am not seeing this on the right side. Some ink will tell you how much contact is occurring.

If you are having this problem with multiple razors, I suspect technique. As said too much pressure and speed are a common problem with novice honers, I believe you went off the edge of the stone, on the right side of the Duck, the scratches look to be about the width of a stone. You can match them up and see.

Stop your stroke an inch or two short of the end of the stone. I try to keep the puddle of water from falling off the edge of the stone. Moving the puddle back and forth across the stone will keep you from falling off the edge and force you slow down and concentrate on your stroke.

You do want to hone the heel. The whole edge needs to be sharp and smooth. Honing heel forward is a good way to hone the heel. I use the whole edge when shaving which is why I like a sharp pointed tip.

Scratches can be sanded and or buffed out, but as advised learning on some less collectable razors may be a good idea. You can buy Gold dollars for 2 bucks, and they can be made to shave, at the least you will learn to hone, they can be challenging and if you completely ruined a razor you’re out 2 buck.

Honing hundred year old razors is just problem solving that requires a methodical, analytical approach. You are at step two of the “Problem Solving Cycle” you have identified a problem, now you have to define the problem (cause) by eliminating factors, slurry, pressure, speed, stone edge, stabilizer height, and control (honing off the edge).

We can advise, only you can identify the problem.

Enjoy