Accl parameter is definitely not the issue either. Since my pocket milling isn't working, I use a boring head to finish the hole. The finished hole is precisely where it's supposed to be. If steps were missed, then the hole location would be wrong.
I believe backlash is also working correctly too. If it wasn't working correctly then, again, hole location would be incorrect.
There's some other issue. And, no, it's not a worn out or mechanically loose machine!