Why has the "note to self" feature stopped working?

[sls3]

I use the "note to self" feature all the time on my Galaxy 5 Android phone to send messages to my Gmail. Apparently after the last update, this feature stopped working. It APPEARS to be functioning, acknowledging my message, but the message never actually gets sent. I haven't changed any settings. The only difference, far as I can tell, has been the recent update. What to do?