Drive does not fit mount - Celestron Motor Drives for Telescopes

I purchased the motor drive for my Celestron 127EQ telescope. The model number was the one quoted by Celestron as the one for the mount. I received the drive from Optics Planet (Excellent service, and price match, by the way, so no issues with seller). However when I tried to attache the flexible drive shaft to the drive screw, the hole in the drive shaft was too small, and would not fit the drive screw. I have not been able to attach to the mount. I have contacted Celestron, but have not received any response as to why the drive motor does not fit the mount.
Pros: Very intuitive to attach to moutn
Cons: The drive shaft did not fit the telescope it was designed for

This review was written in the old system and had content requirements that are different than reviews written today.