Latest Scientific Knowledge & Sarvastivadins

You still think of dukkha as only mental suffering.

See the 3 types of dukkha. Sukha is impermanent, therefore it is dukkha of change. Sukha is conditioned, therefore it is dukkha due to conditioning. Sukha is only freed from dukkha dukkha, unpleasant feeling suffering.

Only the happiness of parinibbāna is changeless and unconditioned. Therefore entirely freed from dukkha.