Something really weird is happening here. I noticed that "top -s1" was not updating; then did 'date' followed by several Ctrl-P key presses to get:
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:20 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# date
Fri May 17 12:54:19 UTC 2019
A# uname -a
NetBSD
A.Culver.Net 8.99.40 NetBSD 8.99.40 (GENERIC64) #0: Tue May 14 09:43:55 UTC 2019 mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/evbarm/compile/GENERIC64 evbarm
I've found the digital fountain of youth. Or tickled some timer-related bug.
Thanks
Mike