Hmm, this could be a server bug on the 1.8 particles indeed, but did you already check your settings in both versions?Even if I disabled those particles with OptiFine, they would still be visible for other players.
The thing is that I don't know why, they suddenly appeared and now I can't disable them. This must be a server bug or something...
Also, I just noticed that those particles only appear in 1.8, I switched to 1.12 and I didn't see them.
Never mind xD I found out where they come from. Apparently those particles are caused because of the dragon that is in 1.8 lobbies. So all players should see those particles.Hmm, this could be a server bug on the 1.8 particles indeed, but did you already check your settings in both versions?
If you don't see anything wrong with the settings and think it is a server bug, you can report the bug here: https://reports.cubecraft.net/bug_report