Can't connect network in USA

[VisitortoNYFlo]

I arrived in New York 2 days ago and enabled the O2 Travel bolt on before I arrived. But since I landed I cannot connect to a network. I've turned on data roaming, tried connecting manually, and it simply says no network available. I use a Pixel 3a which I believe is supported in the USA. My phone had no trouble connecting to a network in the Netherlands during my layover. I'm losing my mind only being able to use wi-fi! Does anyone know what else I can do to get onto a network?

[Cleoriff · Accepted solution]

@VisitortoNYFlo 

The data speeds in the US are absolutely pathetic with UK sims. People generally find using a local sim such as AT&T or T Mobile (which can be picked up anywhere) work much better for data.

[DS8642]

This is exactly the same situation I am currently in. My daughter's iPhone is connecting, but not my Sony. 

Tried all the usual off/on flight mode off/on etc.

My phone worked in Spain last October.