@wsamael I had problems with the SSD in the Nespi 4 but slightly different, I assume though because I use Attract Mode not Emulationstation. Maybe it is the same problem though. Games showed up ok for me, but the romlist is on the SD card so it should. Scrolling through it, so loading media, would be slow then freeze for a decent time before coming back. I followed the guide below and it fixed it for me, maybe it might fix your issue too?
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first