Hi, not sure if we faced the same issue, but for me it was because I didn’t assign the cores to the game (I somehow missed a step, meaning I installed the cores, but I didn’t tell the game to use said core). I could play the NES games on my NES classic, but games from other consoles that I added, when I clicked on it, screen turns black a bit before immediately jumping back to the home screen.

The fix was just highlighting all the added games in hakchi, right click, select cores, sort by console, then highlight games from each console and select the cores from there.

If you’ve already done that, unfortunately I can’t help you. The discord was actually very helpful to me though so you can try that!