Yeah it’s a typo. They generally go unseen when you make them and when you look back hours later you either see them or someone tells you about it. The biggest difference usually being how they tell you. There’s people who do it in a way where you’re just thankful they let ya know so you can fix it, and sometimes there’s people who do it in a weird way where you wonder “are they being condescending or dickish? Are they actually trying to help or do they just want to sound like they know more and that they don’t make mistakes sometimes?”. But It can be really hard to tell, ya know?