is there a bug in ID turning allowances?

Hello there my name is John and i would like to see if anyone else is having the same issue
in ID turning at roughing when you give some allowance it gives it towards to the OD
so i have tryied with a negative number and it works!
BUT in the simulation it shows the piece with negative allowance! does anyone else have the same problem? is there any solution?

Also i need one more advice
when in roughing.... there is always one last pas extra like a "cleaning" pass that doesnt cut any material... how can i get rid of it?

thank you all and sorry for my english

Never had this issue with allowance, I put it in positive and it leave material (OD & ID)... for the rough cycle, you can set the final cut amount to zero and no cleanup will be generated