We are also experiencing the same issue with deleting in-app purchase items in App Store Connect.
We've followed the same steps you outlined, but the IAP items remain after attempting to delete them. We have been in constant communication with Apple for the past month, but they have not been able to provide any help or resolve this issue for us either.
Could you please share what you eventually did to resolve this issue?
Topic:
App Store Distribution & Marketing
SubTopic:
App Store Connect
Tags: