Autocomplete not working correctly


I just updated to the latest version Atom (0.199.0), and the problem has persisted for a while (as long as I can remember) – Autocomplete doesn’t work properly. Whenever I hit ‘tab’, which is the keybinding in settings, some totally arbitrary incorrect completion is rendered. Here is an example I just recorded:


I don’t really know where to start troubleshooting. Any ideas?