As the streaming enabled mode does stream parts, it has a weird behavior that despawns important objects right in front of the player.
When a server is created, there’s a local script that loads our map every second by 4,000 parts. (roughly takes 2 min) We do this since roblox constantly fails at publishing the game.
Here’s a video of the behavior: https://www.youtube.com/watch?v=ZWAYxtpa3G0&feature=youtu.be
You can also test it out here. It typically happens where the “freeway ramps” are.
I’ve had similar issues, although with key parts for my game/testing server which need to be kept at Transparency 1, but they end up seemingly not streaming in at all, breaking the welds they are used for.
currently parts are streamed based on their centers. large parts that have an edge close to the player may stream out before smaller parts with edges further away. when using streaming enabled, keeping the parts around the same size will behave more as expected. i noticed when i fell through, it was a long skinny part that had not streamed in yet.
There are actually a lot of long skinny road parts that load in just fine so I’m not sure that’s the case. Its weird how its just the narrow parts, which are mainly only the ramps.
I should also mention, if the parts are in studio to begin with streaming works fine. If they’re loaded after a user joins that’s when it despawns them.