I built my picade 2018. Everything works perfectly - I have powered with 2 separate cables: 1 monitor and 1 raspberry - none of my rechargers was suitable.
Birth of the problem:
I bought a Aukru 5V 3A charger now.
I’ve attached to picade and connected 10 'screen with HDMI to raspberry USB.
Everything works fine with a single loader. but too bad resolution.
The resolution of my monitor has gone to be blessed. :(
Now the retropie font is grainy and all games show poorer graphics with halos.
Perhaps the charger is not suitable?
The bad bad news is that now, even if I attack the old 2 power supplies - to have separate monitors and raspberry, the graphics are always compromised.
Looks like your Pi isn’t providing the native resolution of the display.
You could try to add:
hdmi_group=2
hdmi_mode=16
to your config.txt file, that will force the native resolution of 1024x768 @ 60Hz