'Waiting for payment' window sometimes pops up uninitiated

[nanostos]

I was just testing out the browser web app and noticed that it would sometimes bring up this window without any user input. The window displayed before this is the QR code window with an amount filled. Refreshing the browser page doesn't solve it (as in, it reoccurs). Not sure under which circumstances this window is supposed to come up or what its purpose is. Seems to take about 10-15 seconds for it to come up after opening the QR window or refreshing the page.