Can't log in / link battle net account

[Nurallaerel]

So I just spent like half an hour trying to link battle.net account.
Tried creating new one. Tried enabling phone app verification. Tried resetting password and use different accounts, e.g. login with Google. Nothing helped.
Best case scenario is when I see 'You're connected' screen in the steam browser, but the game itself was still on 'Scan QR to log in' screen.
Any ideas?