In version 1.4.8, objects started "dissapearing" from Stacked Sectors. This only happens while looking into the stacked sector from the oppisite side. I am not sure when this problem started, as I have only noticed recently.
I tried in GZDoom 1.2.01 (The next latest one I had at the time), and it worked as expected.
Here are two screenshots from 1.4.8 and 1.2.01:
Spoiler:
1.2.01
1.2.01.png (591.76 KiB) Viewed 498 times
1.4.8
1.4.8.png (581.73 KiB) Viewed 498 times
If you look in the top right corner of 1.4.8, you can see that some objects are still there (The white tree staligmite things).
Okay, here is an extract from the map that I suffer problems from. Walking back and forth on the road, looking at the hill above the building should make the trees disappear/reappear.