Please see my reply above to WiderMouthOpen that I just posted.
I'm not using any type of spam call blockers. All calls appear on Call History, including calls that ring my phone that aren't displayed on TV & calls blocked by Cox that don't ring my phone or appear on TV. Calls from all sources have not displayed on TV including robocalls, calls from my 2 cell phones, and calls from my neighbors cell phone and home phone. But it's intermittent - - sometimes the same number does show on the TV on one call but not the next, or fail to show but do Display on the TV on the next call a few minutes later. Cox refreshed the DVR at my request. My email to them included your previous suggestion of reprovisioning but I'm not sure the tech knew what that involved (the actual text I sent is in my reply to WIderMouthOpen).
On a related subject, you asked once if my recordings only disappeared after a Daily Update. The answer is only after the DVR is rebooted for whatever reason. But not after every reboot. Sometimes nothing is deleted for several updates or rebootings. I've been keeping a daily log since 8/25/24, and schedule the updates for 8-10 AM so I can monitor how long each step takes and write down what recordings disappear. I skip 2 days in a row to reduce the chance of disappearances.
I really appreciate your assistance. Many thanks.