short advise
More detailed advise.
What sharpening stone do you have?
Certain cheap sharpening stones are known for not preforming well on higher hardness steels.
I’m a big fan of (japanese) water stones. A quality 1000 grit will get you really far. And should yield you superior sharpness to when the knife was new.
The sharpening systems work. But i don’t see the point of them. They cost a lot more. And usually have lower amount and or quality of abrasive material.
They “fix” an almost nonexistent problem. Keeping the angle a 100% the same every stroke. It’s just not needed. Slightly varying the angle gives you a convex edge. And that’s actually quite nice.
If your convinced you need to keep a perfectly consistant angle. You can also do that freehand on a stone with a piece of 3m dubble sided tape (gray stretchy tape with red liner) and a small piece of wood.
top knife was ground freehand with the piece of wood and sticky tape.
The secondary edge is perfectly flat and at a very steep angle.
If sharpened a carbon #5 the same way. But i actually prefer the freehand carbon #5 on the picture. (bottom)
ps: you tape the thin piece of softwood to the top of the knife. And than you get a consistent angle when the bevel of the knife and the piece of wood both touch the stone.
you can also tape a "handle (empty lighter) to the other side of the knife for easier moving up and down on the stone.