I recently purch'd a new Ruko F11Pro from Amazon, and have used it few hours -- here in metro and neighboring Los Angeles area -- with confusing results.
The most notorious happens at the beach (Manhattan Beach, El Segundo beach) ... I'm wondering whether there is some sort of geo-fence or deflector ... because the quad will approach about 20 meters from the shoreline .... and then it acts as if it was pushed back (west , the ocean --> to east , the land). It does this at any altitude and even on non-windy days. It's like there is some sort of "force field".
Also had another very troubling thing happen just yesterday ... a near flyaway. I was at the beach, on the sand, but well away, 20m, from water. Using up/down stick, I took the quad straight up .... and as soon as it got above 15 meters , it kept rising on its own and (concurrently) drifting farther (south west .... away from beach). I hit RTH, but it kept moving away.
The quad was well within site, but getting visibly smaller.
None of sticks responded ... so I started pursuing it a bit on foot with controller ... and somehow .... using the sticks (or maybe RTH), I got it to move towards me. I kept GPS on, but manual'd it back. I have no idea what happened.
It may have been wind currents, which were 12mph, maybe a bit more at higher elevations.
I've had some other minor close calls .... I'm wondering where this quad (F11 pro) might be "defective". I'm not sure unpredictability or precision (at this price range: $300) is to be expected. But "defective" in modern electronics is an all-or-nothing deal. There are enough self tests and "Okay To Fly" lights and alerts. that makes me suspect poor design.