So it started on saturday when (i think) atom or a plugin automatically updated and started to cause lag when pressing the return key in the code editor.
I started by disabling plugins one by one and found that emmet was causing the problem. I went to the internet to find people had found this problem previously in 2014 and 2012 when there was large changes to the core of Atom.
I then overrode the emmet keybinding for the enter key with the default atom enter keybinding.
Come to today i have had no problems but realised that the enter key no longer works after this change to my keybindings. If the keybinding is there the code editor has no lag going to a new line but in dialogs such as create file or duplicate file i cannot press enter to confirm them. If the keybinding is commented out in the keybindings config file there is lag when pressing the enter key in the code editor but no lag issues elsewhere in atom and the dialogs work fine.
I hope that this can be resolved soon because it is severely restraining my workflow.