FENCE_ALT_MIN doesn't work in SITL

Hi!

I am trying to test the FENCE_ALT_MIN in SITL to prevent copter from going below a certain altitude, but it doesn’t seem to work.

I have set FENCE_ENABLE = 1, FENCE_TYPE = 9, and also set FENCE_ALT_MIN altitude to be both above and below the takeoff altitude. I have also tried with AVOID_ENABLE = 0 and 1, but nothing seems to work. FENCE_ALT_MAX on the other hand, seems to work perfectly fine.

The “MinAltFence” autotest script does pass, but I am unable to replicate the behavior manually. Is there something that I am missing? Thanks.