There is no single "universal" firmware. The Hk8 Pro Max is cloned and manufactured by different sub-suppliers. A firmware meant for a "SmartPro" variant may brick a "JZ" variant. Always verify your build number.
: If the watch doesn't reconnect after the update, delete it from the app, "Forget" it in your phone's Bluetooth settings, and pair it as a new device. HK8 PRO ACTUALIZA FIRMWARE Hk8 Pro Max Firmware Update
: Navigate to the "Device" or "About" section within the app. If an update is available, a prompt for version or higher should appear. Post-Update Maintenance : Users have reported better results by reinstalling the Wearfit Pro app There is no single "universal" firmware