@mvl-dxie, did you ever manage to solve this? Seems like it is still the case, error in App Store Connect: "This email address can’t contain the character "+""

Same issue here. @Apple, not sure if this will help, checking the dev console, the API call that fails is: GET: https://appstoreconnect.apple.com/WebObjects/iTunesConnect.woa/ra/apps/1449819058/pricing/intervals Status code: 403 (Forbidden)