I've bought renewed and open box motherboards in the past and I've had mixed results. The open box boards are tempting and if they work then they can be a great value. Sometimes the original purchaser of the motherboard forgets to remove the Windows 10 product key from the board they're returning and that's a bonus for you.
Based on past experiences, I figure it to be this way with Open Box boards...... there is usually a problem that eludes the technicians at newegg, asus, amazon, etc because they don't perform a comprehensive test. It seems that all they do is hook the board up to see if it works. If it works then they relist the board in the Open Box section. These so called Professionals that test the returned equipment are usually low level (lvl2) technicians.
With the refurbished boards, they sometimes miss the problem or a new problem pops up. With most of the refurbished products I've ever bought, the product breaks within 3 weeks to 9 months but sometimes I find a winner.
I've had good luck with 2nd hand boards.