VBA Formula that require Control+Shift+Enter

VBA automation -
Excel added the formula - but they all return "Not Found"
After the VBA automation - I visit each cell, see the formula is correct and then press Control +Shift + Enter; then the correct value displays! Of course, the curly brackets also appear in the formula bar.

In VBA I tried to use the:
objXL.ActiveCell.FormulaArray = "=IF(ISERROR(INDEX(PositionDataSell!$T$2:$T$505,MATCH(" & lngContractID & "&" & strQuote & strConCat .....
The Excel Formula bar for the cell is just empty (blank)

Using only the Formula property:
objXL.ActiveCell.Formula = "=IF(ISERROR(INDEX(PositionDataSell!$T$2:$T$505,MATCH(" & lngContractID & "&" & strQuote & strConCat .....

The correct formula is created in each cell, but...
Until I visit that cell and use the Control+Shift+Enter - the lookup will not work. It is proof that the right formula is there, without the curly brakcets.

In Excel - my vba code successfully constructs these formulas:
In essence: It checks for an error and prints "Not Found" if no match is found in the check. It test for two values in a row - matches them to two columns on a row in another worksheet, and returns a third value for the matches of the same row.

=IF(ISERROR(INDEX(PositionDataSell!$T$2:$T$505,MATCH(73945&"@"&-10000,( PositionDataSell!$D$2:$D$505)&"@"&(PositionDataSell!$S$2:$S$505),0))),"Not Found", INDEX(PositionDataSell!$T$2:$T$505,MATCH(73945&"@"&-10000,( PositionDataSell!$D$2:$D$505) & "@" & (PositionDataSell!$S$2:$S$505),0)))

and, maybe I also need to think of a way to prevent the users from visiting a cell as well
Maybe I hide the cells with the actual formula and display a cell with the actual value of the cell with a formula?