leaves getting broken off at stem
Certified GKH Gardening Expert
It could be the wind, or it could be that they are being stepped on by a person or an animal. If it is a small animal it doesn't appear to be eating the plant. This could mean that it is a bird, or something looking for insects, and accidentally snapping off leaves. There is little you can do for this case, and the plant will often outgrow the damage that this will do rather quickly.
Unfortunately there is not a lot that can be done here. If you can, temporarily, net the top, then this might help some.