Strange prompt when move row to another sheet- "this sheet contains columns with the same name..."

SYSPK ✭✭✭✭✭✭

I created a blank sheet with nothing on it and didn't change column names or anything. I then made a new workflow in another sheet to immediately move a row when a checkbox gets checked. I did this to test it out, and got this prompt. I pressed OK and undid the checkbox and then saved, but the row still got moved over.

The workflow worked. But should I be concerned by what the prompt says? How can there be columns with the same name since they don't allow for that anyway? I have too many columns in my source sheet, there's no way for me to check that their names are the same. What did Smartsheet "modify?"