Cannot add global pass to account.

On both the Xfinity app and website, I get stuck in the loop: I select my cell for the plan I want to add the global pass to. I enter the location. All green on adding the global pass for either 5 bucks a day or 10 on the website or app respectively (no idea which). Then, I get sent back to my account to select my number again, or just get an error on the app. The Xfinity chat just links me to the article on how to add the pass so that's no help. I'm stuck with no option but to have no data on vacation or rack up an exorbitant bill.