Rename the file .bin instead of .hex. Renaming it will often work, but also make certain whatever the filename is, you never used it before on that printer. Creality has their firmware set up such that every file has to be completely uniquely named.
I installed this in an Ender 3 V2 with a v4.27 mainboard and a BL Touch device and only the Marlin software worked. The other flavor of firmware gave me errors about temperature that were specific to that particular firmware. ON the other hand, the Marlin firmware works perfectly…