Krone RB250 Tie Mechanism Timing

I have used this baler the two previous years with no big problems. Never had this problem. It has an unusual twin string tie that starts applying twine near the middle of the bale, goes to the right side of the bale(looking at the front of the baler), goes left across the full width of the bale, then returns back to the center where the twine is cut. Normally, as the twine returns to the start position it goes across two fixed knives that cut the string. 

What is happening now is that the string moves through the whole process correctly but when returning back to the middle start position it doesn't travel far enough to move the string across the knives to be cut. It stops 1"-2" before the knife. I have searched the operation manual but found no reference for "timing" the twine feed. Can anyone out there help?

Krone RB250 Tie Mechanism Timing