Some manufacturers allow downgrades; others do not. Check the release notes. If downgrading, you may need to use the recovery mode and force-flash the older .bin file.

This motherboard is a popular "Combo" board used to convert standard LED TVs into Smart TVs. Processor: 4-Core CPU 512MB RAM / 4GB Internal Storage Android 9.0 Compatibility: Works for 18.5", 22", 24", and 32" panels 5V / 12V Panel Voltage; Backlight up to 45V 🔑 Critical Service & Resolution Codes

The Sp36811.5 firmware is specifically designed for certain devices, aiming to: