Morning, everyone. Thanks for letting us know about this. We're looking into it now.
In the meantime could everyone (as many of you have already done) let us know which device and browser you're using, whether you're on mobile, desktop or the app, and also send us a screengrab if you can, telling us what page you were on when the pop up popped up.
All that info will help us locate the problem more quickly.
Thanks again.