Anyone can be gracious when they win. Losing is where you find out if you mean it.

Winning makes generosity cheap. You are in a good mood, you have nothing to defend, and praising the opposition costs you nothing because you already have the result. Losing removes all of that, and what is left is whether the respect was real. That is why the handshake after a defeat is the only one that carries information.

After the next loss, do the full version before the feeling passes: find the person who played well and tell them so, with a detail. Save the excuses for nobody. Being gracious while it stings is a small, hard skill people notice.