Could not fetch author data: null value in column "affiliation_country" of relation "journals_cachedauthor" violates not-null constraint DETAIL: Failing row contains (5a2e7121-fcb4-4a94-a4ac-e14c32af6c62, A5016999179, Liangcai Xu, State Key Laboratory of Low-Dimensional Quantum Physics, 22, 633, 0000-0003-4366-3392, 2026-04-07 16:15:03.331417+00, 2026-04-07 16:15:03.331434+00, null, 8, 7, , ["Topological Materials and Phenomena", "Magnetic properties of ..., liangcai-xu).