“On Jun 13th 2024 The Aviation Herald learned that two ribs, that the stand by PCU is being mounted to, were damaged as well as the mounts of the stand by actuator. A temporary repair was done in Oakland replacing the damaged PCU, the aircraft was then ferried to Everett to replace the damaged ribs.”
I wonder if this is related. Details are difficult to find, but an airline memo made public indicated this "loose bolt"
would cause the rudder to stop responding to pedal inputs, but the trim and yaw damper should remain operative.
The F.A.A. said it was monitoring inspections after an airline discovered a bolt with a missing nut in the plane’s rudder-control system.
www.nytimes.com