I have seen others state that Batocera sometimes hangs at the blue (not white) loading screen. I also have this issue (on current 5.20 and previous versions). Sometimes I have to hard power off/on the system several times to get past the hang.
My HW is a Lenovo ThinkCentre 92P Tiny (https://www.lenovo.com/us/en/desktops/thinkcentre/m-series-tiny/m92p/).
I finally learned the doing a CTRL+ALT+F3 will get me to the console so I can see the output and this is what is displayed...
[Xarcade2Joystick] Getting exclusive access: Trying /dev/input/event0
cannot open file en
amixer: Unable to find simple control 'PCM',0