JFC, I have no idea what either a 464d/g or an XX that you mention in a couple of your posts are, but the chip out you describe can certainly be a bit of a problem when routing. It happens in all sorts of timbers and is sometimes an indication of cutting into rising grain on the edge, but not always. Pines of different types are some of the worst woods for doing this and this is often caused by the distinct differences in hardness between the softer spring growth and harder summer growth. Ring porous hardwoods usually exhibit a similar hard and soft growth pattern.
You've tried the breaking the grain trick with a marking gauge, but did you scribe the line deep enough? It usually requires a heavy score to really be effective.
Climb cutting is another option, but this is something I'd strongly recommend you don't do on an inverted router table unless you have a power feeder. Without a power feeder it's all too easy to get your fingers sucked into the cutter. Climb cutting with a hand held router I actually find safer in many respects because you can use the technique to take light cuts to just skim off the outer edge of the wood in two or three stages followed by a normal cut.
In a router table most people set the width of cut first. Once they've got the width of cut set they then gradually raise the router to the chosen depth of cut. Try doing the depth and width setting in a different order, i.e., set the depth of cut correctly and take a very light first cut on the edge. Sneak the fence at the back away from the cutter a bit at a time to get the width of cut. This often helps.
You can often also approach the settings using the edge of the board on the table and the face up against the fence. This way can work well too, but you need to make an assessment of the grain pattern to decide.
That's enough tricks to try to go on with. Slainte.