Capacity Column Formula Is Not Calculating

I have attached a larger section of my spreadsheet.

As you can see in the sections above the "Non Working Section" at the bottom
of the Metro Spreadsheet tab, the figures in the "Capacity" column are supposed to calculate the amount the tank can hold based
on on the last inventory reading entered in the Inventory tab. For example, in the 2nd "This Section Works" section at the top
of the Metro Spreadsheet tab, 6091 was entered at 5 pm. The figure is subtracted from the tank size of 17800. 17800 - 6091 =
11709. The figure you see in the "Capacity" column.

Now look at the "Non Working Section" at the bottom of the Metro Spreadsheet tab. 2140 is the 5 pm figure found in the 0274/1970
row. The 5 pm figure should be subtracted from the tank size. 10450 - 2140 = 8310 should be the capacity reading but the cell
shows 10450, the tank size. Why are the cells in this section not calculating properly?