Why do my formulas stop working when I save, close, and then re-open my spreadsheet?

I am copying a formula that pulls data from the immediate group of cells below in the same column. the formula is =MIN((G6:G20>0,G6:G20)). When I copy and paste and change the cells in the formula so that the same formula is now pulling data from the immediate group of cells across in the same row, the formula also works just great. EXCEPT, when I save. close and re-open the workbook, and I change the value of one of the data cells, the formula output displays #value.

What I am trying to do is I have one of 4 options that go in the data cells - 0,1,2,3. I want the output cell where the formula is to display the lowest option greater than 1. So if all the cells to the right of the formula cell have the number 3, but one has a 2 and another has a 0, the output cell will display 2 because that is the lowest number greater than 1.

Do I need a different formula since I am now pulling data horizontally instead of vertically? Is there some way to protect the formula? It doesn't appear to be changing, so I'm not sure why once I re-open, now the correct answer won't appear.