EDNS buffer size is different between RHEL8 and RHEL9 while using unbound, bind or dnsmasq

Issue

• Why EDNS buffer size is different between RHEL8 and RHEL9 while using unbound like below?

  In RHEL9
  
  [root@rhel9u0 ~]# dig @localhost redhat.com
  ; <<>> DiG 9.16.23-RH <<>> @localhost redhat.com
  ; (2 servers found)
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48338
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
  
  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 1232   <<<===
  [..]
  
  In RHEL8
  
  [root@rhel8u1 ~]# dig @localhost redhat.com
  ; <<>> DiG 9.11.36-RedHat-9.11.36-3.el8 <<>> @localhost redhat.com
  ; (2 servers found)
  ;; global options: +cmd
  ;; Got answer:
  ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1576
  ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
  
  ;; OPT PSEUDOSECTION:
  ; EDNS: version: 0, flags:; udp: 4096   <<<===
  [...]