First, check if the rotary attachment has been correctly calibrated to turn as much as the software tells it to. 

• If not, see Wrong rotation>>to troubleshoot. 
• If the rotary attachment is correctly calibrated, check if you have the correct "rotary mark type" set.

If you are using EZcad,

1. Check if you have “split mark” chosen. 
2. Set the "split size" to less than 5mm.
3. Test again.