codesearch.debian.net shows the following timers with a RandomizedDelaySec of 12h, which will likely run into the same problem.
fwupd_1.5.7-5/data/motd/fwupd-refresh.timer [Timer] OnCalendar=*-*-* 6,18:00 RandomizedDelaySec=12h Persistent=true apt_2.3.11/debian/apt-daily.timer [Timer] OnCalendar=*-*-* 6,18:00 RandomizedDelaySec=12h Persistent=true plocate_1.1.12-1/plocate-updatedb.timer [Timer] OnCalendar=daily RandomizedDelaySec=12h AccuracySec=20min Persistent=true python-certbot_1.18.0-1/debian/certbot.timer [Timer] OnCalendar=*-*-* 00,12:00:00 RandomizedDelaySec=43200 Persistent=true josm-installer_0.0.1+svn18171/josm-installer.timer [Timer] OnCalendar=*-*-* 00,12:00:00 RandomizedDelaySec=12h Persistent=true
OpenPGP_signature
Description: OpenPGP digital signature