It's hard to see how a blade won't "hold an edge any more".
Over the life of a well used and resharpened knife, the blade will get smaller as each sharpening removes some metal. This is natural and unavoidable. As the cutting edge moves towards the spine, the blade material will get thicker. This will require more concerted effort to produce a new sharp edge when you're sharpening as you have to abrade more material (assuming a consistent edge angle).
One way to address this is to reprofile or re-"break in" the edge by establishing a secondary bevel at a flatter angle. For example, if you like your cutting edge at 20 degrees, establish a secondary bevel at 17 degrees, then put on the cutting bevel at 20. Systems like a Lansky make this relatively easy.
Another possibility is that if the blade has been put in a rotary powered sharpener or sharpened on a belt grinder (or similar) it is possible that the blade has been heated to the point of changing its temper. That will make it harder to sharpen and possibly make it prone to chip easily.
Would be neat to see a picture of the blade.
Regardless, Buck can replace the blade. For non-warranty replacements, I think it's well under $10.
