I was placing partition walls, and as I finished with a section, the museum wall itself disappeared, and the window that was on that wall became a weird default window. Sadly I have no idea how I managed to make the bug show up, so I cannot provide any steps.

Later edit: Deleting the partition section does not seem to fix the visual issue. I sold the fancy window, that seemed to fix the visual bug.

Later later edit: I was able to reproduce the bug, I will include a video.