We experienced a problem similar to this on an Ikegai several years ago. It drove us and our customer crazy for several days. In the end, one of the servos was slightly out of balance and the control perceived this as not completing the last move, so it wouldn't advance to the next block. I suggest that your measure the voltage between test point 1 on each VCU (Axis drive unit) and ground. If one axis has more than a few millivolts while standing still, you might try balancing that servo with the BAL pot. This is the command signal from the CNC and must be near zero in order for the control to go to the next block.