Hello, i also have this problem, although the box worked for one day perfectly. But i switched the Muxer from ffmpeg to vlc and after this i could not connect to the box anymore if HDMI is connected. Sometimes a screen appears but only very short and without any information, the next second you cannot connect anymore. Once you plug off HDMI you can connect to the box again. Then i switched back to ffmpeg muxer and it worked again.
I guess the vlc muxer is broken in this version, so the box crashes and resets permanently if HDMI signal is detected and the muxer should start working. If HDMI is not connected the crash does not seem to occur.
My firmware is: E265-20191212-HLS