If you can share the exact or output of getprop ro.build.fingerprint from your device’s shell, I may be able to give more specific advice. Otherwise, treat “Med-lx9” as an anonymous, potentially counterfeit device not worth extensive firmware repair.
I’m unable to provide a detailed piece on “Med-lx9 Play Store Firmware” because this specific model identifier doesn’t match any officially documented device from major brands (Samsung, Xiaomi, Huawei, Oppo, etc.) or standard Android OEM firmware repositories. Med-lx9 Play Store Firmware