I read in Spanish and English, So i usually take a look to see wich language has any chapter, And as you guys can see there isn't any flag on the captcha.
@Wolfraing I tried on both mobile and PC and the flags show up fine. Tested with English+Spanish and English+Japanese. Have you tried accessing MD with different browsers? If other browsers don't have the same problem, look into whether you have any type of scriptblock or adblock running for MD, and disable them if yes. Also you could try clearing cache and/or site data to see if it fixes the problem