https://community.qualtrics.com/XMcommunity/discussion/23284/enforce-a-different-response-pattern-for-each-row-in-matrixAs per your use-case of choosing 2 columns in a 4*6 matrix, there will only be these combinations of choices(users can move it up n down), correct me if I am wrong.
Which would mean 3 per column.
You can include a custom validation of scale point count is less than or equal to 3 and greater than 0 for each of the 4 scale points and show the error accordingly.
Hope it helps!

Thanks. That's a good start. But notice that if, in the 4th row, we move the checkmark from Column 1 to Column 2, and in the 5th row we move the checkmark from Column 2 to Column 1, the counts are still correct but there are duplicates cross the rows.
I ended up having to write a LOT of validation code, checking to see if each response pair equals what was selected Row 1, or Row 2, or Row 3, etc. (and I had to read-up on how Qualtrics validation handles combinations of "and"s and "or"s).

Hi R100 ,
Please try this below logic.
Don't forget to enable force response option.
Hope it helps.
I want to thank HULK0596 for his assistance.

Hi. Thanks, but counting isn't sufficient. In the image, below, the counts are fine, but Row 4 still duplicates Row 2, and Row 6 duplicates Row 5.