I am submitting my app to Apple Store, but it was rejected because of this.
“We are unable to complete the review of your app because your in-app purchase products still have not been submitted for review.
To resolve this issue, please be sure to take action and submit your in-app purchases and upload a new binary in App Store Connect so we can proceed with our review.”
I have that same issue (although my subscriptions have been created in appstore connect) but will deal with it later (next week) as they also asked for some other changes ( they requested to move the registration page after the IAPHUB paywall and it caused a lot of issues in my app). If ill figure out the subscription part before next week Ill post it here, good luck.