IP addresses do not have a 1-to-1 correspondence to data centers or to country locations. The load balancing schemes that Google uses are too complex for that.
How did you discover/choose the IP address that shows your index page (188.8.131.52)? Some IP addresses seem to access experimental or test versions of the SERPs - that is, they never go into wide-scale distribution on the various Google domain names. Sometimes they even may hold a version of the index before certain filters are applied.
However, if you were initially sent to that IP address through the load-balancing logic and then decided to revisit specifically by choosing the IP, then there's a lot more hope that you're seeing a return of your index page.