Seattle Times says Collins identified 353 actuators with the faulty seal assembly delivered since 2017. But only 9 are in the US, all are with United, and all have been replaced. So that is all right, we can relax.
The Boeing fix is for both pilots to apply maximum force to the rudder pedals until the rudder 'unsticks'. What happens when it comes free appears to this SLF to be potentially problematic.
Boeing knows of two incidents with stuck rudder pedals from 2019: did these incidents result from failure of the same actuator, and if so why was nothing done about it?