Why are the odds moving in Trump's favor during the DNC?

Harris started the DNC as the Presidential favorite by over five points. She is now behind after three days of hype.

While there has been very limited polling that has come out during the convention, the Presidential odds seem to be moving against the Vice President during her own convention. Is it possible that the expectations have been set so high as to make it almost impossible to actually reach them?

Obviously the first night was a throwaway as they finished up with back to back to back Bidens and that lasted well past midnight EST. They had the Obama night on Tuesday, which had everyone on the left creaming their pants. Last night was Bill Clinton and Tim Walz with a surprise speech from Oprah - you get a free Oprah speech, you get a free Oprah speech, everyone gets a free Oprah speech. Again, for some unknown reason, Walz was pushed past prime time where he gave by all accounts a fairly lackluster speech. He did, however, let everyone know that they owe it to the public to let them know how they will govern if elected, before tell us nothing about how they are going to govern.

Now is the finale. The question will be whether or not the Democrats can muster up the organization to the point of getting Harris on before most Americans go to bed. That being said, perhaps pushing Biden and Walz back to well beyond prime time was not an accident and perhaps they will decide to do the same with Harris? Perhaps that will be the plan. Keep her off the stage till only the true faithful are left to watch. After all, they really seem hell bent on keeping her out of the spotlight and in the shadows and so far it has been working as well as they probably could have hoped. Why change it up now?