Tested personally with a couple of GameShark for GBC 4.0 but I've seen reports of other devices not working either.
The GameShark menu works fine and will even boot into the loaded game but when trying to activate cheat codes via the switch the the game will either becone corrupt or, more often, nothing will happen and no codes will be loaded.
I would actually like game genie/shark functionality built in so we don't need a tower of power. Especially since my game sharks are having trouble even booting anymore
Tested personally with a couple of GameShark for GBC 4.0 but I've seen reports of other devices not working either.
The GameShark menu works fine and will even boot into the loaded game but when trying to activate cheat codes via the switch the the game will either becone corrupt or, more often, nothing will happen and no codes will be loaded.