I installed the Channels DVR on Windows 10. It does not see any of my premium or HD channels. The HDHomeRun app on the same machine sees everything without issue.
Can you post a screenshot? Where are you not seeing those channels?
When I go through the configuration screens.

Firmware is the latest. I re-scanned the HDHomerun primes (2) and i have most of my channels now. I did have Cox out here last week with cable card issues, so they probably needed re-scanning (although Media Center is fine, has all channels).
I'm missing some of the HBOs and Showtimes now and probably some others. In the Channel Linesups for the HDHOMERun Primes shows the missing channels.
Are they the hidden channels?
HDHomeRun PRIME (1314489A)
467 channels (0 favs, 166 HD, 39 hidden)
DVR: USA-CT06408-X"
Please check the channel lineup on my.hdhomerun.com to see if all the channels appear there or not. You can also scan from there, as well as hide/unhide channels.
The Channel Lineups on both HDHomerun Primes my.hdhomerun.com show all of my channels. I did scan from here. But the guide, and when I click on the 467 channels in the settings some are missing. BTW, I'm running the DVR Server on a Synology DS1515+ if that makes a difference.
How do I unhide the hidden ones?
Click the gear icon in the HDHR section and select Scan network. That will refresh the channel list from the hdhomerun.
To unhide click the red x icon.
The gear is greyed out and there is no X.

The gear is at the top right, next to "2 hdhomeruns found". It's cropped out of your screenshot.
The red x are visible on my.hdhomerun.com or in the dialog when you click "467 channels", next to each hidden channel.
Note that any DRM channels are automatically hidden as Channels and Channels DVR do not support DRM. That's why HBO and other channels do not appear.
That explains that then (DRM). Although a few HBO and Showtime Channels are showing and kinda work, but not really.
On my.hdhomerun.com you should see "DRM" next to any channels affected. Usually it's premium channels but depends on your cable provider.