Symptoms
The redirect to store is configured for Markeplace link in CCP v2 or "Buy new subscription" link in CCP v2. Clicking "My Account" link leads to "Session expired" when store is loaded from CCP.
Cause
The issue is caused by the bug with id #PBA-83579 ("Shared brand secret does not work for new session").
Resolution
Please contact your TAM/pta-team to get information about the status of the bug.