People eventually learn whether your kindness was character or strategy.

Strategic kindness has a shape people eventually recognise. It appears when there is something to gain, fades when there is not, and is distributed according to usefulness. Genuine kindness is less selective and less well timed, and over a few years the difference becomes clear to anyone paying attention.

Check the distribution of your own. Notice how you treat people who can do nothing for you: staff, strangers, someone whose moment has passed. If there is a gap between that and how you treat the useful, close it deliberately. That gap is the one everyone else can see even when it is invisible to you.