Sometimes a 'Sending...' notification shows up in the bottom left when I use trello. I think it happens when I mispress/mistype a key. It may be related to this keybind I have ctrl+\
1. What causes this?
2. What happens with this 'Sending...' notification?
Note: I cannot provide screenshots because it happens so suddenly and unexpectedly that I don't have the presence of mind to take a screenshot.