You might want to consider the issues I pointed out in this post:
CSS Mode Not Working Correctly.
Basically I found that the VFD is not programmed from the factory to use the braking resistor, even though there is one installed. When I called Tormach on this they agreed with my finding but have never since followed up.
Without the braking resistor enabled the spindle can and does coast more than it should especially when using the 3-Jaw chuck. Until I modified the VFD programming to use the braking resistor I found many situations where spindle speed was going faster than it’s programmed speed when beginning a cut as pointed out in my post above.
Maybe PP2 has become more sensitive to this issue and now throws an error when it sees that the speed is higher than it should be?