please reproduce: rc.httpd force-restart stops, but does not restart, httpd

The command
# /etc/rc.d/rc.httpd force-restart
does not work for me. It successfully stops all httpd processes, but does not restart them. The output is:

1. (98)Address already in use: AH00072: make_sock: could not bind to address [::]:80
2. (98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
3. no listening sockets available, shutting down
4. AH00015: Unable to open logs

I can reliably reproduce the behavior on two different Slackware-64 15.0 nodes by

1. running pgrep -a httpd (to verify httpd processes are running),
2. running rc.httpd force-restart, and
3. running pgrep -a httpd again (to verify the restart failed).

I suspect a timing issue, where httpd is not fully stopped yet when the restart begins. But before I start to work on it, can anyone else confirm this behavior with Slackware-64 15.0?