Let's check these assumptions:
In layout setup / show records from, you have Daily Itinerary selected.
In portal setup / show related records from, you have Daily Tasks selected.
Enter layout mode and double click each field in the portal row. can you confirm that each field is from Daily Tasks?
Finally, if you enter Manage | Database | Relationships and find the two "boxes" that define the relationship for this portal, they are named exactly the same as the text in Show Records From and Show Related Records From?
Finally, make sure that the fields in the portal are fully inside the boundaries of the portal.
Thank you so much.
I went through your checks and found that In portal setup / show related records from, I did NOT have Daily Tasks selected.
That solved the problem.
Very much appreciated.