Delay propagating to just 1 server of DNS Cluster

[masernel]

I have a DNS cluster (master-slave), today upgrades NS1 from Debian 11 to Debian 12 and after that the DNS propagation to NS1 takes about an hour (not sure the exact duration). Before the upgrade it was propagating straight away. No wait time.

I have the following servers:

• webserver.domain.tld, Debian 12, HestiaCP 1.9.4, Bind 9.18.41 with mydomain.tld
• ns1.domain.tld, Debian 12, Hestiacp 1.9.4, Bind 9.18.41
• ns2.domain.tld, Debian 11, Hestiacp 1.9.3, Bind 9.16.50

Before upgrading NS1 to Debian 12, its configuration was the same as NS2

At webserver.domain.tld I create a TXT DNS Record test.domain.tld with value test

From my computer I execute

dig @ns1.domain.tld test.mydomain.tld TXT → record not found

dig @ns2.domain.tld test.mydomain.tld TXT → record found just seconds after creating the record

I keep checking NS1 for the record and about an hour later, the record is found

When I create the record I check the /usr/local/hestia/data/queue/dns-cluster.pipe which has the content /usr/local/hestia/bin/v-add-remote-dns-record user mydomain.tld 10

I am wondering how the propagation is being done. If someone can explain it to me I appreciate.

When I create a DNS Record it is added to the queue file. When is the command in the queue file executed and which command/service executes it?

Once the command is executed why is it propagating straight away to NS2 but there is a huge delay to NS1?

Any help is much appreciated!

[masernel]

There is an issue in the documentation at DNS clusters and DNSSEC | Hestia Control Panel

Is written to add the following line to master:
# Add this line, if adding multiple slaves

also-notify { second.slave.ip.address; };

I changed it to include the NS1 as follow:
# Add this line, if adding multiple slaves

also-notify { first.slave.ip.address; second.slave.ip.address; };

Then restarted bind service and created a record. It was propagated straight away for both NS

I suggest the documentation is updated. The line also-notify must have all the slave IPs