A Microsoft app for iOS and Android devices that enables authentication with two-factor verification, phone sign-in, and code generation
Note : I am not a Microsoft employee and the responses are based on experiences and best effort.
Since you are using Gmail with Tabs view, I'd recommend you use the "All Mail" option to see all mail. You may also want to check your "Spam" Folder.
If you have successfully setup verification in the past, then you may want to check your Rules in GMail to see if the emails are getting deleted.
If you are still not receiving the emails, you may need to see if you have to use other Recovery options for your account.
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