I’m sure the problem is simple, but I don’t know what the problem is called, what causes it, or how to solve it. This happens even in Roblox, not just in Roblox Studio, and I’m annoyed by it because I add a lot of details and suddenly it starts making my build ugly.
Graphics settings on Roblox and Roblox Studio mess with render distances. From your video, it seems to me like your graphics are set low- which is the cause of the render distance.
By default, Studio’s Editor Quality Level is set to Automatic. This means that studio adapts the quality level to your device’s performance. However, you can set the Quality Level specifically to a level you like by navigating to:
File > Studio Settings > Rendering > Editor Quality Level
You can then choose a quality level that you like. This is useful if you want to see your build in full beauty. Many developers, including me, set it to level 21 (max), because we’re willing to sacrifice some performance to see the many benefits of seeing our full game during editing.
You can also change the graphic level in normal Roblox by opening the Roblox logo menu, settings tab, and changing the Graphics mode from Automatic to Manual and adjusting the slider.