Sphinx 2.25.2 – ANAFI Ai (anafi2) falls through the ground, UE4 magic tile stays empty

ANAFI Ai
1

Hello,

On our Sphinx bench the ANAFI Ai no longer stays on the ground: right after spawn it
falls through the terrain and keeps falling forever, upside down. The ANAFI UKR, on the
same machine and in the same session, behaves normally. The same Ai setup was flying
fine a week ago.

Setup

  • Ubuntu 24.04.4, kernel 7.0.0-38-generic
  • parrot-sphinx 2.25.2, parrot-ue4-landscape-ecosystem and parrot-ue4-empty 2.25.2 (build 20260507)
  • Firmware: anafi2-pc #latest (7.7.3, last-modified 2026-05-20)
  • GPUs: RTX 2060 with NVIDIA open driver 595.99.02, plus a GTX 1060 with no driver loaded

Launch
sphinx “/opt/parrot-sphinx/usr/share/sphinx/drones/anafi_ai.drone::firmware=https://firmware.parrot.com/Versions/anafi2/pc/%23latest/images/anafi2-pc.ext2.zip”
parrot-ue4-landscape-ecosystem (same result with parrot-ue4-empty)

What we observe

  • Ground truth, read with tlm-shm-dump on the omniscient_ai section: worldPosition.z
    goes from the spawn height (266.8 m) down to -1500 m and beyond, about 23 m/s, with
    worldAttitude.x around 3.13 rad.
  • The omniscient___UE4__magic_tile_ai section stays at zero on every field, while
    omniscient___UE4__magic_tile_ukr is populated.
  • The UE4 log does register the drone (“Boot uuid” matches the instance ro.boot.uuid).
  • The only Sphinx error is “[StateMonitoring.cc:68] Failed to detect landing after 10 seconds.”
  • On the drone side: no GPS fix, takeoff checklist reports gps, gyro, magneto, baro and
    vcam, and TakeOff is ignored. The front camera shows the scene upside down.

What we ruled out

  • The Ai alone, without any other drone: same result.
  • Without the -gps-json option: same result.
  • landscape-ecosystem and empty worlds: same result.
  • with_front_stcam=false: same result.
  • Different pose_offset values, including a spawn 0.5 m higher: same result.
  • Firmware dropped with “fdc drop firmwares” and downloaded again: same result.
  • The UKR (anafi3_milp, 8.4.0-rc2) in the same session stays on the ground at 266.7 m.

The only change we can identify on the machine since the Ai last worked is the
installation of the NVIDIA kernel module for this kernel.

Questions

  1. What can prevent the UE4 app from providing the magic tile for one drone model only?
  2. Is the anafi2 model known to need a specific GPU or driver setup with Sphinx 2.25.2?
  3. Is there a log or debug option to see why the tile is not created for this drone?

Thanks for your help.