There are some smart contract functions that do not have a return value and defining the interface will result in an error. There are also cases where the same function name has a different return value.
I am not following @SolExpDB. Do you think the solidity compiler error is wrong or that the vscode extension has autocompleted or quickfixed in a way that generates a compiler error?
@kanej I think this is a bug in the vscode extension, some functions with the same name and arguments but different return values are not buggy. But there are some functions that give an error