@crinrict there's similarities, but it's not the same thing :/ Nothing under the roof shows up in the reflection for me, not just the windows but not even the walls. I'm launching the game now to check if it happens outside of Sulani, because I don't think I've seen anything like that before.
I am back with TESTS! I couldn't try to get a reflection in another world's "natural" water, but I was able to confirm that the walls do reflect in swimming pools, even in Sulani, so the reflection in ocean water is the only problem. However, while testing I realized I do also have the bug that started this thread, as no window or door will appear right in the pool.
I'm linking two photos in Sulani. In the first, there's a swimming pool and the reflection of both walls and roof (but not the windows). In the second, you can clearly see the two roof pieces, but no walls. I also checked my settings, and my reflections are on "Medium," not on High.
Is there any expectation of correction for this bug? It will soon be two years old. :S
