G900X, G950, G1000, Cirrus Perspective®, and Embraer Prodigy® systems with GDU software versions 15.20 and earlier are affected.
Loading GDU software versions 15.10 through 15.20 may permanently lock saved waypoints. Updating the Jeppesen navigation database on systems with GDU software versions 15.10 through 15.20 may also permanently lock saved waypoints.
Follow the procedures outlined in the attached Service Advisory (“1729A” – see below) to capture and re-install the saved flight plans.
This issue has been corrected in GDU Software Version 15.21.