The cause of the issue was custom permission lists assigned to customer rather than delivered PTPT1000 and PTPT1400.
To validate that, assign Peoplesoft administrator/Portal Administrator role for testing purpose to user and retest if user is getting same error again or not?
If it worked, then ensure you have assigned delivered permission PTPT1000 and PTPT1400 list to user. If that is custom, you could try below steps and see if it helps:
Add the permission list PTPT1000 & PTPT1400 in Structure & Content: Root > Fluid Structure Content > Fluid Homepages > My Homepage & NavBar
and run portal sync
Let us know if this helps and resolves the issue.