Heyyy, everything is correct, those 9 drones were visual bugs! They had already been used but were still showing, that was the problem!
Nothing was lost! Each drone is used up when it waters a tree. Your 9 drones already watered your trees today (you received the HIVE rewards in your wallet, "HiveGrove Drone" transfers). The drone icons were still showing on the trees even after the charges ran out, which is what was hiding your new one. That's fixed now: you have 1 drone available, so arm it on the tree you want.
Ok maybe glitch cuz I swear they write showing when I started posting. 🤦🤷 Thanks for looking into it