Hi,
I use Fusion360 and have not had that problem.
It looks to me like you are using MultiplePasses....is that correct? The shape final shape of the object looks to me like the machine has done the first pass but only partly completed the finishing pass.
May I suggest either turn off the MultiplePass option, and leave StockToRemain at 0.
There is suggestion also that the LeadIN/LeadOut is playing silly buggers with the toolpath. May I suggest experiment with Ramp and turn off LeadIN and
LeadOut. I usually use Ramping toolpaths, in part because I do quite a number of circularly interpolated small diameter holes with even smaller endmils for which
LeadIn/LeadOut would mar the hole, but have now just become accustomed to using it eslewhere.
Craig