Another very quick post. It occurred to me that my old TomTom, after dusting it off, did not retain time. I could set the correct time, and within minutes, it would switch back to 0:00. Very annoying, of course, but there is a fix. I did not create it, but I'd like to share it.
The quick and easy fix can be found at: https://www.rima-lock.com/tomtom-urban-rider-K3-WNRO-fix.htm
It solved the problem for my TomTom Rider Urban/Pro, and I hope it'll help others too.