@OP, does this mean that if you're in the same location or something, you don't need a verification?
if use the same IP and same device they do not send the code by sms, but if the person uses a different IP and a different device, then they send sms with the code.
I figured it out, he won't be asked
only if he decided to not use 2FA on a specific computer, but if not, 2FA will always be required
(will be asked for the code sent via Voice or text message / Google prompt).
So, I ask again how could the supposed hacker access the OP email?
I only see one possibility, someone used the OP device
If he didn't receive any code or prompt, then he should take this one in consideration, especially if there is someone who also uses the same device.