I think Trump was at something like -13 in Rasmussen last week. As I said then, those polls simply reflected a brief shock over the riots and looting and perhaps a feeling that Trump wasn’t taking control of the situation fast enough. But since then he largely has, and the polls bounced right back.
Wait till the effects of his rallies kick in.
I find the idea of asking a subjective question like “Do you approve of Donald Trump” sort of strange. Could it be possible one disapproved of Trump because they think he is too mean and should stay off twitter, but will vote for him anyways?