Currently systemd-timesyncd tries to connect to the NTP server quite
early at boot-up. At this time the network connection has not been
established yet. This causes resolving the NTP server to fail and
a rate limit kicks in which makes systemd-timesyncd wait for 30s until
the next attempt.
Lowering the retry attempt to 10s makes systemd-timesyncd connecting
shortly after.
Note: The rate limit is 10 attempts per 10s. Because the attempts are
immediately exhausted lowering connection retry attempt below 10s
adds no benefit.
See also: https://github.com/systemd/systemd/issues/24298
7729db1e11