Skype login "something unusual"

When I try to login on the laptop to my Skype/Microsoft account, I get "We've detected something unusual about this sign-in. For example, you might be signing in from a new location, device or app."

I know my password and I'm logged in on the phone, which is using the same router.

Microsoft does not send a verification email to the email account (Gmail) associated with the account. If I choose "I don't have these [i.e. the said email account] any more" and a non-Gmail contact email address, verification fails.

Any ideas? Thanks for reading.