Why are you using Ocarina in 2020? Gecko OS is Ocarina with more features and came out 10 years ago... Plus it supports SDHCs, basically the only normal-sized SD cards on the market now. Good luck finding 'normal' SD cards that will still work with Ocarina in 2020, they don't make them anymore because a 2gb card is utterly worthless in the modern day.
As for your problem, it sounds like you're using the wrong file format. Cheat codes should be saved as .gct, not whatever format you're saving them as. I'm surprised these apps are even picking it up... They must read the game ID, and then only look for a codes folder with said game ID in it regardless of file format. I've never saved anything other than .gct files in my codes folder so I wouldn't have noticed anything if this is the case. I'll have to set up my Wii again and experiment.
Also, if you aren't already, use Ocarina Cheat Manager (there should be download links somewhere on the internet) to compile all your codes into a GCT with ease.
EDIT: Throughout my time hacking games and such, I've always found that some codes just refuse to work regardless of being the right region etc.. When I used to hack on MKWii, a lot of BullyWiiPlaza's codes would never work on my Wiis. There was no obvious reason as to why as any other PAL MKWii code worked without issue.