Terrain Following not working with LidarLite

Hi all. Trying to get terrain following working an a FreeFly Astro with a Garmin LidarLite V3HP. The issue doesn’t seem to be the LidarLIte, as the altitude_terrain value is updating as expected. I’ve got MPC_ALT_MODE set to 1, which should be terrain following, but it’s not changing altitude at all as the terrain below the quad changes. Flight log is at https://logs.px4.io/plot_app?log=46ac83f3-53f3-48e4-a96d-f667938d7202. Not quite sure how to upload the .param file, but MPC_ALT_MODE is set to 1.