Does this happen to anyone else?

My 9 month old has become very distracted bf. This morning she would only latch a minute or two before stopping to look around and was totally done after maybe 7 mins. I still left very full so I am sitting here “pumping” but literally nothing is coming out. It’s been 12 mins. I know it’s not the pump parts because I replaced them recently.

What’s going on?!

** this has happened before. I just don’t get why. I pump everyday at work (3 sessions).