I remember my first very timid try with the
MA in my back garden. Just start, take off fly a few meters for and backwards and then my attempt to return to my take-off position. I got crazy, since the
MA simply did not want to return to where I wanted it.
Untill I realized, that about 1,5 meters from the Take-Off was the wall of the house. The front sensors simply did not want to come that close to the house. So I made a 90° yaw and then pulled it back sidewards.
At other locations, I thought I was fine to land, but the sensors again indicated, that there was a problem. Sometimes it was "just" the grass I wanted to land on, sometimes the dirt. I got one of those flexible Helipads you can pin to the ground and now use that to start and land. Since then, never had an issue with sensors telling me that the landingarea was not suitable for landing.
I guess, that you are simply to close to objects for the sensors to feel comfortable landing. You might see (and think) that it will fit, but the sensors might have other parameters to keep a safe distance to obstacles.