Check if you have uploaded all required screenshots and all details for all active languages. The error happens on my side usually when I forgot to add a detail for a second/third language.

I just had a call with Apple Developer support. Same s*** (sorry) as yesterday and the day before: it's a known issue it's in progress there are already tickets for it it won't be published on the system status page as only "some" clients are affected I won't be notified when the bug is fixed, just try again tomorrow. Well, thanks for nothing!

After your app is approved, it can take up to 24 hours to go live on the App Store. (https://help.apple.com/app-store-connect/#/dev34e9bbb5a)

Yeah, there are several other threads here, all facing the same issue and one thing in common: no reaction or statement of Apple.

No, there is no other way. Rating property is required and has to be set in App Store Connect. The rating of your app for the purpose of parental controls on the App Store. Note that while the rating is set for each platform version individually, the final app rating will be determined by the highest rated platform version for the app and will be displayed in the App Information section. (https://help.apple.com/app-store-connect/?lang=en#/devf29afbb74) Your selections are converted into an App Store app rating as well as additional territory-specific app age ratings. (https://help.apple.com/app-store-connect/#/dev599d50efb)

Same here