Duplicate (Triplicate and more!) Topics being posted

[daunk]

Since upgrading to v4 (.2.8) from v 3, some months ago we've been having regular duplicate and triplicate or more topics being posted - they are identical, and don't seem to have a pattern. Initially we wrote it down to fat finger and multiple pressing, but it happens very frequently and even with mods who say they didn't do this. I activated flood control but I believe this only affects posts within topics, as it doesn't appear to have reduced the incidences of these multiple topics. Has anyone else experienced, or have any ideas? 

 

[Genestoy]

I also am getting this with 4.2.8 and almost daily, got a triple post yesterday ?