How do I stop auto open of the next email when I delete the previous email?

When I delete a message, the next email automatically opens. Please, how do I stop that? I have the split view, love it. I have the add-on: Select Messages - which is wonderful! Every time I delete a message it opens the next message, I don't want the next message opened. I don't want the message to appear in the split screen until I click on it. So I have to put a check in Select Messages and then click Mark As Unread, and then uncheck Select Messages so the message doesn't appear in the split view any longer. All that, with every email, so there is nothing showing in the split view. I can't imagine what the purpose of auto open is.