Sign in window that won't go away

Hi,

Not sure if this has already been raised, but this sign in window keeps popping up on the desktop site (using Chrome) and I don’t know how to get rid of it.

smarketssigninwindow

Even after entering my email and password the box just reappears immediately after, and upon refreshing the page it reappears immediately too. I need to close the tab and open a new one for it to disappear, but even then it often reappears shortly after.

Also I’ve noticed it appears whenever I open Chrome dev tools.

May also be worth noting that the tab shows the spinning loading circle whenever the window is displaying.

Thanks,
Calum