Sounds like this should go under bug reports - many people are reporting the opposite, that Interactive Rendering is now better than ever with the options, so this would mean the problems you are experiencing would be a bug rather than a general discussion. Of course, that means in order to have a look we'd need Corona version, Max or C4D version, OS, computer hardware specifications, video grabs of what you mean would be nice, information on whether this is all scenes or just some (or particular materials).