WinMax 2 2023 How to downgrade bios to 0.35?

after updating to version 0.41, cannot downgrade anymore back to 0.35. the new version is very poor performance. poor stability. always errors, always crash. and the flash not allow me to downgrade. how to downgrade? because now the WM2+G1 is completely unusable. Mad same flash to USB push f7 and the PC start to flash than restarts with nothing happened.