The first commercial break (following the monolog) for The Late Show with Stephen Colbert never gets detected as a commercial. This is probably because the first part of the break begins with a picture-in-picture of the band playing and the commercial itself. However, even when this switches to just the commercial, that isn't detected either.
The comskip executable included in Channels DVR is a third party app. https://www.comskip.org/
It will never be 100% accurate.
You can search the forum here, or the comskip forum for how to tune your comskip.ini file.
Unless some user here has experimented with the comskip.ini settings to do exactly what you're trying to do with the exact same show and can tell you what to change. And changing the settings affects every video comskip is run on.
Unfortunately, the comskip site's link to their forum does not work.
It does appear to be missing. His main (home) webpage still works https://www.kaashoek.com/
I don't waste time tuning comskip.ini, so haven't been to the site for years.
It typically only takes a few moments to go in and manually tweak the commercial breaks using the CDVR Edit Commercials option in the WebUI or iOS. I pretty much do it for all my recordings, as it takes very little time, especially once you get the hang of it.
You'll end up with a better result that way, than you ever will tweaking comskip.ini...
The main issue that I have is logo detection, I watch a lot of sports and pretty much all of them have logos but for some reason comskip will not always skip commercials even if the logo is missing.
For example, the PGA tournament was on NBC this weekend and the NBC logo was only on screen during the broadcast. For every commercial even the side by side ones the logo at bottom left was missing so they should've been skipped. It was a fairly small logo.
For the average user, this is no doubt the quickest and easiest way.
For recordings I watch and delete, I just use skip/advance.
For recording I want to keep (ad free), I use my video editor (VideoReDo) to remove the ads and find that the comskip results are mostly wrong, missing or mis-identifying ads.