Why am I not getting my two step verification from websites like twitter?

[Android Central Question]

On Twitter I have a login and password and also have set up to be emailed a code to enter on twitter to verify it is me. I just switched from a samsung S7 Edge to a Google Pixel 2 XL. Since being on the google phone I am not getting my notifications from twitter with the verify code. Why is this not working.?
Thanks Mark