DNS error passing upstream server flags

[wbsygs]

Prerequisites

• I have checked the Wiki and Discussions and found no answer

• I have searched other issues and found no duplicates

• I want to report a bug and not ask a question or ask for help

• I have set up AdGuard Home correctly and configured clients to use it. (Use the Discussions for help with installing and configuring clients.)

Platform (OS and CPU architecture)

Linux, AMD64 (aka x86_64)

Installation

GitHub releases or script from README

Setup

On one machine

AdGuard Home version

v0.107.64

Action

I had the server set up a public DNS service and an intranet DNS server as upstream, confirmed it and then tested the intranet domain using dig.

Expected result

Normally, recursive DNS server flags should return qr, rd, ra.

Actual result

It did return results for the domain I set up.but It turned out that the returned flags had qr, aa, and ra in them, incorrectly keeping the upstream server's flags.I also found out afterward that if it's read from the cache, it will.

Additional information and/or screenshots

$ dig srv.home.arpa

; <<>> DiG 9.18.30-0ubuntu0.24.04.2-Ubuntu <<>> srv.home.arpa
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40948
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;srv.home.arpa. IN A

;; ANSWER SECTION:
srv.home.arpa. 1200 IN A 10.4.0.3

;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Tue Jul 29 18:58:29 CST 2025
;; MSG SIZE rcvd: 58

$ dig srv.home.arpa

; <<>> DiG 9.18.30-0ubuntu0.24.04.2-Ubuntu <<>> srv.home.arpa
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36825
;; flags: qr rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;srv.home.arpa. IN A

;; ANSWER SECTION:
srv.home.arpa. 1199 IN A 10.4.0.3

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Tue Jul 29 18:58:30 CST 2025
;; MSG SIZE rcvd: 58