Comment 5 for bug 1891586

It would be good to understand the severity of this bug, and what it is blocking for you.
Juju should be restarting "gracefully" on a failure such as this. If it is continually failing and not able to progress, then it is certainly something worth investigating, though the fact that "systemctl" is returning a timeout isn't something we can control particularly well.
If the issue is that this sort of failure is preventing juju from cleanly restarting, then that is a different thing (also very much worth investigating).