Worked on the MHSanaei/3x-ui repository to address a critical frontend reliability issue affecting VLESS xtls-rprx-vision flow persistence during inbound option reloads. Using React, TypeScript, and Vitest, implemented a state management solution that guarded against premature clearing of user-selected flows, ensuring stable client configuration even as inbound options were reloaded. Developed a regression test with React Testing Library to verify flow persistence, reducing the risk of configuration errors and connectivity failures. This work enhanced UI resilience during dynamic state updates, aligning with business needs for reliable client connections and lowering support overhead through improved frontend robustness and automated test coverage.