As of October 2016, if you are searching for products that are not native to your country location, you will notice that the Google shopping results will not show up. Before when you for example visited google.co.uk and search for a product you would get shopping results among text ads. Or if you go to google.co.uk/shopping you would see products relevant to the search. Instead what you see in the Shopping Search is a blank page and only text ads on Web Search.
Not really sure why they did this, but can assume that Google only wants to show products that are native country to the searchers country location. Which in a sense is a good idea, as I manage allot of Adwords clients, I think this is a good move. However it has created a little wake of issues for people who need to check results in a country not native to there location. This problem is for agencies, freelancers and individuals that want to visually see shopping ad results.
Currently there is no real work around and recommend to do two things :
Currently there are three methods :