return / enter key not working when composing or replying to messages

When typing an email the return / enter key does not seem to work. It works with all other programs so I am confident it’s nothing to do with the actual keyboard. 

Hello Todd,

I can confirm that with all installations I have seen, Enter and Return keys worked. Please make sure that in Menu > Tools > Settings > Shortcuts you accidentally didn’t set these keys for any actions.

Russel 

No shortcuts set for this. I have completely uninstalled and reinstalled and the weird
thing is that I can send one email and it works, and then the next email I try to send it won’t. If I reboot the computer it will work once and then not again. Enter key works for every other application I have tried, including typing into this web form.