Router rebooted in the early morning. Recording was interrupted. Didn't restart. Couldn't continue recording. WHY?

Recording the Open Championship. My router rebooted in the early morning. Recording was interrupted. OK fine. When I started watching the recording this morning and realized I had an interrupted one, I attempted to restart the recording both in the guide and then starting the live showing. But it won't allow it. Only after I deleted the recording was I able to restart the recording from live forward.

WHY?

Why do I have to delete the interrupted recording to start a new recording of the same program? I was totally happy having two separate recordings but I had to abandon the first portion just to restart.

Searching shows this has been this way for years.

That's really odd. I've never seen that. It's so robust, that any of my interrupted recordings, always restart as many times as they need to, until the end of the timer for them. I can see that by looking in the log file. Not sure why some go interrupted, but if it's just a glitch in the stream, it SHOULD keep trying to restart by itself, until at least the time duration of the original timer set for that show.

It doesn't create a second recording in my case, it stitches the file together as many times as needed.

Is your tuner still connected and at the same IP address?

No idea if DHCP gave it the same IP when the router came back up. I've now set a static to ensure it remains the same were this to occur again.