when i try to sign in to yahoomail on web, i get asked for 2FA. so i unlock my phone and tap on the notification to 'Approve' my sign in. Unfortunately,i then get asked to sign in to the android yahoo app..once i do, i get two notifications to 'Approve' sign in for.
I've just tapped the tick on both.

.funnily, if i had just launched the yahoomail app first, i will only get one notification to approve the web sign in, no signing in on android required...