Well, in some comic arcs, Iron Fist lost his powers as a result of a magical backlash or when he overused his chi energy. Sometimes, it was part of a larger plot twist to challenge his character.
Iron Fist's power loss in the comics often occurred because of external magical forces beyond his control or internal conflicts that disrupted his chi flow. Different storylines presented different reasons for this, but it usually led to an interesting development in his character journey.