Microsoft have released a new update for the first generation HoloLens. The update KB4489899 takes the build to 17763.379 (from 17763.316) and does not have any new features but there is an improvement in tracking and device calibration. Microsoft say about 10 to 15 minutes after the installation HoloLens users should see an improvement, but Microsoft recommend resetting the holograms for best results.

The update will come down via Windows Update.