Linear actuator's fully automatic cyclic operation results in slow, unstable reference drift.

Good morning. 

Our non-standard CNC production line has been upgraded to use electric linear actuators for station pushing and shifting. The single-stroke positioning accuracy fully meets the standards.

However, after prolonged continuous fully automatic cyclic operation, the stroke reference slowly shifts slightly. Each time it's reset to zero, it slowly drifts again after a few days. I've carefully checked the mounting bracket and locking structure; there's no loosening or displacement. I've also checked the drive signal and found no interference.

I suspect that the actuator's internal transmission experiences accumulated slight elastic deformation under frequent alternating loads, affecting the long-term repeatable positioning reference of the CNC system.

Can anyone help me solve this problem?