I think it's fair to say Corbyn has been kicked from pillar to post.
Well yeah. This is what happens to highly visible public figures even before you factor in that Corbyn has followed a career path that typically doesn't result being the leader of the opposition and 'PM in waiting'.
To run the show, you need to have believed that you can run the show for some time, and over that time, you would have needed to have taken actions and made decisions mindful of your ambition*. Corbyn did not do that (or rather, his ambition wasn't to run the show), and neither I think did Milliband - they were kind of opportunistic in their leadership bids which whilst is fine, kinda, it does not grant you any kind of media 'free pass' - the opposite in fact. You have a credibility debt.
misinformation in the press surrounding Corbyn
Out of interest, what misinformation? Is it possible to list it, or is it just a sense of it?
* as an aside, as I understand it apparently May always believed she could be PM and she wanted to be PM. She was in Cameron's cabinet because she was a direct threat to him as leader. She was in the tent pissing out.