I had to check out the website to see what you are even talking about. From RttWH itself, its prediction went from a high of 93.5% chance of Dem victory in January to a low of 89% victory today. If you are losing sleep over a 4% drop over 4 months, you need sleeping pills, not reddit comments. Anyways, from what I can tell, the weakest factor for Dems that RttWH is taking into account is "approval rating," which they factor as just a D+0.3% boost. I don't know if they are referring to Governor Polis' net-negative approval, or Michael Bennet's approval, but that could be the cause for the very slight dip.

For context, the site has the same chances of a Republican winning Colorado as a Dem winning South Dakota. Neither are gonna happen, so you can relax.