Queue length changes between browsers

I have a sizable queue. When I work on it for 40-60 items, and then begin to close the tab, I get a pop up that asks if I want to leave. I click Cancel, and then I get another pop up that says remnote has been sync’ed and it’s safe to close the tab. When I open remnote on another device, i get a totally different number, and it may even be higher than when I began on the previous device. Can anyone explain what is going on?