Spill ranges turn into arrays after closing the file

Hello all,

I have written some spill formulas in a workbook and they work very fine. I'll give an example:

=SORT(UNIQUE(FPL[Area]))

However, after closing and opening the workbook again, all my spill formulas turn into arrays and I lose the references do the data table, that turn into ranges.

{=SORT(UNIQUE('Focal Points List'!$D$2:$D$986))}

After this the spill ranges stop working correctly and I lose the readability of having the column names in the formulas.

Any clue on what is happening?

I'm using Excel 365 for Enterprises version 2202.

Regards,