Download/Update to 3.5.8
You can update from Plugins page or install from
Summary
- Timer
in checkout if confusing 
and it seems to customer that if he doesn’t send within that time, his payment is lost - If time reaches 2 min or so, customer is basically left with nothing to do
as he knows he cannot complete payment in that time - A modular UX clearly indicates that the timer is for price refresh and address stay the same
