Bug introduced in 11.1.0 and persisting through 11.2.0
I have just discovered that
Tooltip works differently from as described in the documentation, at least in my version of MMA (18.104.22.168, Windows x64). Below are two screenshots from
Tooltip documentation page, the first one was obtained before evaluation (tooltips are correct, labelling every curve) and the second one after the cell evaluation -- tooltip shows now its full argument. Is it a bug?