I have multiple Wii's and the remotes work on those. I tried also launching into an app the other day with a gamecube controller that I borrowed from a friend and it black screened. I am afraid that it may be a flash issue like @morning_glory has said with the corrupted saves and the flash is, unfortunately, going bad. I have no idea, what or how, to even fix that. It could be bluetooth as well... I just don't know.The issue with the remotes disconnecting could indeed be related to the Bluetooth. Since all your remotes are official and you've tried different ones, it might be worth checking if there's any interference nearby. Also, you could try resetting the Bluetooth module on the Wii. If that doesn't work, it might be a hardware issue. Consider reaching out to a repair specialist if you're not comfortable troubleshooting further.