I too get this issue and boy did it suck when I was running film cams back in the day.
As previously mentioned, it's all about heat and motion. This time of year when the temps rise and cool so much mornings and nights, the shadows are cool and the sunlight is warm so edges of shadows turn into triggers. Any dew on the lens of the cam can create such issues as well. There's not a whole lot you can do about it other than turning the sensitivity down.
I don't mind the random triggers as it sometimes catches the deer that are further out in the field and never would have triggered the cam. Might tell you the deer are entering or leaving from other spots vs near your cam.