Travel day allowances?
If you look at the screenshot below, breakfast and dinner were provided and it only gives $5.5 for lunch. That is not 75% of lunch per diem. Here is Concur’s explanation:
I am currently investigating your case and I was able to confirm all meals travel allowance rates are set for each location, then adjusted for provided meals. The first and last day of the trip are first calculated as 75% of the full allowance: 75%*66 = 49.5. Then the system will deduct the full meal allowance for breakfast = 16.00 and the full meal allowance for Dinner = 28 which amounts to 5.50.
I was able to confirm, the provided meal deduction for each meal is not prorated. The system will calculate 75% of the full meals rate and then the system would deduct the provided full meal rate for either Breakfast, Lunch, or Dinner. Basically, provided meals are reduced at 100% not 75% on travel days.

Add a misc. expense type to make up the difference if wanted. Remember each expense type over $25 requires a receipt.