Hey there!
Not entirely sure this is the same bug but it seems similar
Previously (when the bug did not occur) I was instantiating parts on the server and having them not anchored from the get-go. However, this caused my game to have some bad performance issues as I was creating and removing a lot of parts constantly.
I got an idea to have the parts be anchored on the server and have the clients remove the anchor once they replicate, that way the server does not have to deal with all of the physics.
Which lead me to have this issue, once the parts spawn, they remain in the air even though their “Anchored” property is set to false, I’ve also noticed that once my character comes closer to the part physics wakes back up.
My guess is that because of how the Network Ownership works, the parts’ physics owner is the server until the player gets close, which then it switches… Now that’s great and all, but it does have some edge cases like this.
I would give physics ownership to the player but due to the nature of the game, any given player can be around that said part…
I’ve asked some friends if they can replicate this issue a few days ago, and @1TheNoobestNoob got a gif of it!
