this usually happens when changing the location of particle form replicated for example workspace.
Also there is anothe property of particle emitter that work some reason only shows up sometimes that has an option to be “loop”, which basically just hides the whole particle.
There are two reasons I know about which might cause this, one is that server displays it much less detailed so that it does not affect server performance, so on client it would be more detailed, and secondly is your graphics quality in your Roblox and Roblox Studio settings