I suspect the problem with those fairly soft stainless steel knives is that the burr really just flops back and forth and you never remove it properly (it should be abraded off to leave a smooth, sharp edge) and when it breaks off instead, you get a dull knife that won't come back with a steel. Stainless knife steel is also fairly abrasion resistant due to the carbide structures even if it's not particularly hard, so the edge can stay messy even as you remove large amounts of metal. Very annoying.
The Ikon, on the other hand, is like the Forschner my mother had for decades and never used because it cannot be sharpened on inexpensive oil stone -- skates around like crazy and stays blunt. Did OK with good synthetic watherstones.
For soft stainless, you certainly should not bother with high grit stones, they are intended to be maintained with a steel. I would sharpen to 20 degrees, or 25, with a coarse stone until all nicks and bright spots are gone and a definite burr has developed. Use light pressure, or the burr will become huge. Switch to a finer stone, say 1000 grit and work the burr of very gently, with easy light passes on both sides until it's barely there, then steel and see what you have.
If that doesn't work, draw a burr on the 1000 grit stone again and then strop on cardboard or a 3000 grit stone to abrade the burr off, use light pressure, the last thing you want to do is bend the burr back and forth until it breaks off, as that will leave you with bright spots and a dull edge again.
A good steel is your friend with "soft" stainless. Murder on a very fine edged very hard Japanese knife, but a steel is how you get and keep an edge on soft German Stainless.
And some knives just won't get or stay sharp, even after you grind forever to get the dented, blunted remains of the edge off. Very soft stainless rolls away from the pressure on the stone, I think, so you are just bending a fairly blunt edge back and forth, never actually getting it sharp.
Carbon steel, on the other hand, isn't very abrasion resistant and the burr will remain small and easily removed. Edge wont' last as long, but will wipe back up with a steel easily until enough is flattened or broken off to require abrasive sharpening.
Peter