Does the "Tool Path Simulation" look like that? "3 Hrs" Wow that sucks. Shouldn't take more than 3-4 minutes tops. Looks like the 1/2 "Stock Allowance" is not being removed by the 1/8. What tool path strategy
did you use? "Area clear" "Bevel Carving". Is your tool dia. the same as dia. in your tool libary? i.e. if your tool is smaller dia than library info the tool will "back off" the cut.
Looks like you used "Area Clear" with 1/2 and 1/8. Try "Area Clear" with the 1/2 tool. Then "Profile" using the 1/8. Be sure to adjust the final depth of the "Profile" pass to the same depth as the "Area Clear". Or you'll cut all the way through your material thickness,if its set.