The SOA TTLs for internal.admin.swh.network were set before they were updated in puppet, with the old (way too low) values.
Update them with decent values instead:
olasd@pergamon:~$ (echo update add internal.admin.swh.network 86400 IN SOA pergamon.internal.softwareheritage.org. sysop.softwareheritage.org. 19 3600 120 604800 120; echo send) | sudo nsupdate -k /etc/bind/keys/local-update
(19 is a valid serial for this zone)