If the disc popup appears and then kicks you back to the Wii Menu, that usually means the loader can *see* the game, but the game itself is failing to boot.
Since your own dumped game works, your cIOS setup is probably fine. That narrows it down mostly to:
* bad/corrupted WBFS files
* wrong folder structure/naming
* incompatible transfer method
* broken SD/USB formatting
A few things to check:
* Make sure the games are in:
`sd:/wbfs/Game Name [GAMEID]/GAMEID.wbfs`
(same structure as the working dump)
* Use Wii Backup Manager to transfer the games instead of copying manually. It fixes filenames, IDs, split files, and formatting automatically.
* Verify the SD/USB is FAT32 with 32 KB clusters.
* Some downloads are RVZ/NKit/ISO and were converted badly. Try another known-good dump.
* If using SD card loading on real Wii hardware, compatibility can be hit-or-miss depending on the loader/cIOS setup. USB is usually more reliable.
* Try changing the game's IOS in USB Loader GX settings:
* IOS249
* IOS250
Some games only boot properly on one of them.
The important clue is:
> your own dumped game works
That almost always means the issue is with the other game files themselves, not the homebrew setup.