No 4G coverage with NA Verizon Pixel in Europe?

I'm in the process of finalizing a trip to europe where I will visit a number of countries including Ireland, UK, France, Italy, and Spain. I decided to check out what Verizon offered for international plans and saw they had an interactive planner. Pretty neat I thought. I put in my countries, selected what phone I'd be using, and expected full compatibility. However, the chart that returned showed only 3G compatibility in all countries. Even the coverage map maxed out at 3G. If I repeated the same steps with my wife's iPhone 6S, it got full 4G coverage in all countries. Is it simply because it's locked, or is there something preventing the Pixel from getting full use of the 4G spectrum in Europe?