See, you admitted for the experience to be free from suffering, the condition has to be that there’s no desire there. It’s different from Nibbāna which is unconditioned. Anything conditioned is not nibbāna, not permanent freedom from suffering.
So
is true because of the conditionality you presented above. Dukkha of conditionality. Experience itself can never be Nibbāna, even the experience of nibbāna, that experience itself is not the same as the object of nibbāna. Because experiences are conditioned, and nibbāna is not.