Accurate Cartesian positioning in industrial robots remains challenging under drift, friction, and regime changes. This paper presents an uncertainty-aware, two-stage compensation pipeline for a four-degree-of-freedom (4-DOF) serial robot using only joint telemetry. Stage I combines a long short-term memory (LSTM) point predictor with an auxiliary network that learns per-axis prediction intervals (PIs) via a loss balancing prediction-interval coverage probability (PICP) and mean prediction-inter