What I believe you did highlight is the current inability to recall a sitting US Senator. From what I read, only the Senate chamber can remove one of its members.
This may bear some thought on how to change this for the better, as no one should have this distinction of having no accountability to the state one serves or the people of that state.
If the 17th could be repealed, then the recall ability should reside with the electors, in that case, the Legislature.
If not, I'd still like to have the ability to recall Representatives or Senators. We can do this on the State Level, we should be able to do so on the Federal Level, too.