[V21 stable steam] Ground combat - Armor issues

[thixotrop]

1) Soldier sprite vanishes with Buzzard and (new to me) Sentinel armor when landing. I don't know what is triggering it. With Buzzard it is very repetitive, roughly 2 out of 3. With Sentinel only 1/10.

2) Sentinel armor can go through roofs of desert house.

The selected soldier (green air-tile above roof) entered the house from there.

3) Is it intended that Predator armor can't use stairs?

Or is this some special of this custom map (Skitso or Stinky)?

Sentinel armor can use these stairs.

If Predator armor is used in such a ground combat and there is no passage somewhere (north in here), these soldiers would be useless. Unless you destroy the pipeline, which I did, despite the fear of explosion/fire/black stuff coming out.