PPSSPP validates the game’s CRC32. If your cheat DB lists a code for ULUS-10389 but the CRC doesn't match your specific ROM region (USA vs. Europe), the emulator will silently ignore the entire file.
If you’re still manually entering hex codes into PPSSPP, you’re doing it the hard way. To get the most out of your PSP library—whether it’s 60FPS patches, HD texture fixes, or just infinite health—you need a solid Why use a pre-made Cheat DB? Massive Library: cheat db file for ppsspp better