Thank you Dustin for your prompt reply. The nightly reboot did not resolve my issue. My recordings are still gone. In fact, today when I look at my scheduled recordings screen the bar that shows DVR hard drive memory usage now indicates 1%. Last night it was 42%, even though all my recordings were gone. I also noticed on my iPhone Contour TV app, in My Library, in Recordings, the listing of all my old recordings are now gone. They were still listed last night, even after the Contour DVR no longer showed them. The app must have synced up over night.
To address your questions to me: there have been no recent changes swapping a QAM host set-top box with DVR. In fact there is nothing that occurred recently that might have caused this issue. It just happened out of the blue.
I do not have a cloud DVR. My recordings are on the Contour box DVR hard drive. But somehow they are listed (or at least were) on my Contour app. I don't think I ever could view my recordings from the iPhone app.
I do not know what caused this issue. It seems like the Contour DVR box just lost its identity with me and my Cox account, as if it was a brand new box/DVR ready to be configured and set-up. This started with the remote no longer working and needing to be re-paired. I then had to go through basic initialization steps such as selecting a language and giving the box a name (e.g. Living Room). I suspect doing this wiped out the recordings on the hard drive.
I will do as you suggest and email Cox tech support with my info and a link to this forum thread. Perhaps they can dig into my hardware records and figure out what went wrong. Worst case, I will have to get a new Contour box at my local Cox store.