@alvin thank you very much!!
now it works!
sorry for the inconvenience, solution was really simple and I didn't find it on Google

Hello! I installed Recalbox on my Raspberry Pi 4 today (surprised that balenaEtcher is no longer needed to burn the image). Recalbox boots perfectly when I install it, until I restart it or turn it off and on again. Screen appears black as if there is no device connected.

Can someone help me? thank you!