Refund after flight change to same date and itinerary as original

I was randomly checking date change options for a I class (Business Light) flight I booked few months ago. It shows me $10 total refund if I select same as original itinerary for 2 pax all included. I find it weird it even allows that. And it shows the change fee as 0 in the final page. If I change the date, it does show a change fee.

Since the fare code is same as original, am I missing anything by doing this change? If need to make further changes in future, it shouldn't effect right?