Unable to view recently added subscriptions on Portal or facing error when adding them to the Subscription Allocation.

Issue

• Subscriptions are present in the account but are not displayed when trying to add them to the Subscription Allocation.
• Added subscription to the Subscription Allocation on the Customer Portal but when viewing it on the portal it shows the below:

No attached subscriptions found.

• Adding subscriptions to the Subscription Allocation fails with the below error,

 Subscription allocation information is not available