Just don't kick yourself too hard yet for not buying a new drone verses a used one. I bought a new
Mini 2, but all the 4k videos had a Green Bar running across the bottom and I had to return it. Luckily I bought mine from Costco and their return policy is like, "I'm so sorry that you had this problem, how do you want your refund?"
Actually, I only wanted to exchange it, but they do not do exchanges, they refund the purchase price and if you really wanted a different one, you then go back into the store and buy another. I did buy the Care Refresh from DJI when I activated the first one, so I had to change the drone on the policy. That was also a snap, I scanned the Refund Receipt and the new Purchase Receipt and provided them a photo of the new drones serial number from the box and they emailed me the new policy the next day.
So, like I said earlier, don't beat yourself up, even a new one could be defective. All of the refurbished, used ones sold through DJI or its stores go through the same testing and some bad ones (new and used) will always get through.