Critical issue in Debian 12 with resolv.conf, postfix, bind9?

Hi!

I think I've found a problem that few people know about, and it concerns postfix, bind9, and resov.conf.

Since I've had a lot of problems after upgrading the server from Debian 11 to Debian 12, such as slow system performance, Postfix reporting an unknow hostname, etc., I decided to run some diagnostics comparing a clean system with Debian 12 and Debian 13.
I did the tests on virtual machines, installing debian-net.

I installed a clean system, then ran apt-get install bind9, and then compared the DNS response to commands like dig -x 8.8.8.8, dig -x 8.8.4.4.
On Debian 12, the results are terrible, and despite entering nameserver 8.8.8.8 in resolv.con, nothing improved, but on Debian 13, the results were fast and correct.
On the production machine, Postfix frequently reported "unknow hostname."
The problem on Debian 12 was "solved" after adding entries to bind9:
forwarders {
8.8.8.8;
1.1.1.1;
};
On the test machine, Debian 12 also sped up after adding this entry, but on Debian 13, simply adding these entries to the resolv.con file resulted in an immediate improvement.

I conclude that in Debian 12, neither bind9 nor postfix read the entries in resolv.conf.

Please verify the problem.