An apology with no change behind it is just a pause before the next time.

Words settle a moment and behavior settles a pattern. When somebody says sorry and nothing afterwards is different, the apology stops meaning regret and starts meaning this cycle has a resting phase. People learn that quickly, usually quicker than the person apologizing does, and after two or three rounds the words arrive as noise.

If you owe one, name the specific thing you will do differently and keep it small enough that you will actually do it. Then let the change do the apologizing for a while.