Hi all, new to the forums, and in need of some Mastercam guidance. I'm relatively new to the software but understand most of it (I think). I am working on a one off flange project, 304SS with a .125" deep profiled pocket. On the roughing routine I am using a helical entry, full depth with .250" 4fl coated carbide EM. spindle at 4000 (~275sfm), .0012 CPT, 15% dia woc on a High speed horizontal milling routine within Mastercam.

Everything on the left side pocket when just fine, but on the right, there is a tighter area where I think some of the trochoidal settings may need to be tweaked. I ended up breaking the endmill in this area. Based on what I see from the surface finish, everything looked good, and then where it broke it looked like the toolpath deviated from the 15% and went full burial (reference pic). Any idea why it would do this?

Stumped and this project is really frustrating me. Any help is greatly appreciated.
Thanks in advance!
-Bob