There is a data-flow bug between ndt and the EKF:

[LPARKOUR]

When use_autoware_pose_covariance_modifier in
/autoware/src/universe/autoware_universe/launch/tier4_localization_launch/launch/pose_twist_estimator/pose_twist_estimator.launch.xml
is set to true and GNSS reception is good, the final localization output is taken from the GNSS branch (i.e., /localization/pose_estimator/pose_covariance_modifier_node/selected_pose_type = “gnss”).
As a result, the pose_estimator/pose_with_covariance topic shown in Figure 1 is actually the output of the autoware_pose_covariance_modifier node, not the output of ndt_scan_matcher.
This breaks the closed loop between NDT and the EKF, so the NDT diagnostics keep throwing errors (see Figure 2), which in turn prevents the “Auto” button in RViz2 from being enabled and keeps the vehicle from starting to drive.

Figure 1：

Figure 2：