I’ve found a bug in the copy of the /etc/NetworkManager/dispatcher.d/20-chrony script that comes with Leap 15.5.

The script has a command, "$chronyc onoffline > /dev/null 2>&1", which is supposed to run whenever the script is called with $2 having the value of "up" or "down". To that end, there's a script line that filters out all but "up" and "down" network events:

> # For NetworkManager consider only up/down events
> [ $# -ge 2 ] && [ "$2" != "up" ] && [ "$2" != "down" ] && exit 0

Problem: that first term, "[ $# -ge 2 ] &&", should be removed. Its only effect is to prevent "exit 0" from running if there are fewer than 2 arguments to the script. But, that only ensures that if 20-chrony is called with fewer than 2 arguments then the "$chronyc onoffline > /dev/null 2>&1" line executes, which is certainly not what the author intended.