Creative Cloud log in repeatedly opening

Over the last couple of days, our students and teachers have reported a change in behaviour of CC log in prompt. Previously, when the user would log onto the Mac a Safari web page would open asking the user to sign into Adobe. If they did not need to sign in, they would close the window and continue to use the Mac without interuption. However, over the last couple of days, if the user closes the Safari window without signing into Adobe, every 10 minutes they are prompted with a fresh safari adobe login window again. 

Anybody any ideas why this may be occurring?