A supercritical nonuniqueness example on a graph roughly isometric to the square lattice

There is an explicit deterministic connected simple graph G of maximum degree four, roughly isometric to the nearest-neighbor square lattice with uniform multiplicative-plus-additive constant 100, for which ordinary common-parameter iid bond percolation satisfies p_c(G)<=9/10 and P_(19/20)(at least two infinite clusters)>2200741829/6461571200>1/3. Every root has positive survival probability already at 9/10. Edges internal to opposite quadrants are retained; every other edge is replaced by a private 100-edge chain. Independent coarse probabilities p and p^100 are an exact series reduction with a bijection of infinite components. An elementary quadrant dual-parity count gives survival at least 143/245, while an all-start/all-length weak-bridge count is strictly below 27/107648. The five-page note refutes an explicitly declared all-supercritical interpretation of Benjamini's 2013 Problem 9.6: uniqueness for every admissible graph and each fixed p_c(G)<p<=1. The original problem sentence omits its probability quantifier; the preceding chapter discusses the supercritical regime. No uniquely intended missing quantifier is attributed to the author. A weaker near-one uniqueness claim, critical nonuniqueness, almost-sure multiplicity, exact cluster count or simultaneous-in-p law is not asserted. No transitivity, 0/1/infinity law or uniqueness monotonicity is assumed. Bounded subdivision, series reduction, parity and path counting are established methods. Older hyperbolic-sector nonuniqueness, high-density uniqueness, critical product examples and the annealed stretched-lattice series method are credited with their actual model and parameter limits. Bounded primary-source, native Zenodo, live-register and read-only local-state checks on 22 October 2026 authenticated no earlier full-target publication or solution DOI. This is not exhaustive novelty, exclusive firstness or current-openness certification. The earlier project PR1348 is an unpublished proof source, not an existing published counterexample. Catalog 10000037 / AMR-099-0037 is one result family; source/dependency DOIs are references only. The proposed deposit consists of the five-page PDF and a complete editable source and exact-verification ZIP. A new standard-library checker tests 2048 finite corner-containing dual-boundary sets, all 64 bond configurations of a small series replacement with 192 connectivity comparisons and its joint law, a 4392-vertex metric patch with 2116 sampled pairs, 200 explicit weak paths, exact rational constants/tails, and nine false controls. These finite diagnostics supplement the written infinite proof and do not certify universal quantifiers or priority. AI tools were extensively used in planning, mathematical exploration, proof development and reconstruction, computation, literature investigation, writing, editing and adversarial verification. Alec Kriebel is the named human author. The preprint is unrefereed, without conventional independent human peer review, journal acceptance or formal proof-assistant certification; internal AI audits do not provide these certifications. Authored prose is CC BY 4.0 and authored code is MIT licensed.