Hi Max, also check out this link here: http://moi3d.com/forum/index.php?webtag=MOI&msg=3557.5 for another description why that type of arrangement ("crossing" edges meeting up at a single juncture between 2 curved surfaces) is more difficult to fillet or chamfer than you might think - usually there will be a kind of tiny fillet piece trying to be created at the juncture area.

It can be better in a case like this for the cutting surfaces to have their edge endpoints fall directly on the other edges making those juncture areas which then yield little fillet segments.

In the meantime one way that may be possible for you to get the chamfers is to use surface/surface chamfering to build some chamfer surfaces and then cut those to try and fit them into place. Surface/surface chamfering or filleting is when you separate the object into individual surfaces and then select just 2 surfaces at a time and then run Fillet or Chamfer. That can generate a surface in cases where the edge based one gets confused by how to deal with pieces colliding into one another.

I've attached a version here where I've done surface/surface chamfering to build chamfer surfaces where you wanted them, but if you inspect their ends you'll see how each piece overshoots the other, it's this shallow overshoot that is difficult for the edge based filleter to deal with when it tries to intersect them with each other. Intersecting surfaces that meet in a shallow angle tends to be difficult, there's more of a sort of "zone of overlap" than a crisply defined intersection curve.

If the cutting objects endpoints were kind of staggered with the other outer surface's ends rather than directly on them it can be an easier situation to fillet.

Anyway hope this helps to explain why it's more difficult than it seems.

- Michael