Paypal Pop up won't close

We’ve been using paypal for years with Keep , about 2 months ago we started experiencing an issue where the customer will choose to pay using paypal on our order form, then get a pop up that won’t close for them. Its a never ending loop that won’t allow them to proceed with the order AND the page seems to have a memory because no matter how much they try to reload , they can only get rid of it by using an incognito browser. I’ve alerted Keap to the problem, and they have said its fixed but we keep experiencing this. HELP!