Quad9 DNS server failing

### Prerequisites

- [x] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) and found no answer

- [x] I have searched other issues and found no duplicates

- [x] I want to report a bug and not [ask a question or ask for help](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a)

- [x] I have set up AdGuard Home correctly and [configured clients to use it](https://github.com/AdguardTeam/AdGuardHome/wiki/Clients). (Use the [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) for help with installing and configuring clients.)

### Platform (OS and CPU architecture)

Darwin (aka macOS), AMD64 (aka x86_64)

### Installation

GitHub releases or script from README

### Setup

On a router, DHCP is handled by the router

### AdGuard Home version

Latest

### Action

Replace the following command with the one you're calling or a
description of the failing action:

I am using Quad9 DOh. It started failing from last couple of releases. Its only happening with QUAD9 only.

Reproduce.
1. Use two servers Quad9 Doh , Controld DOh.
2. SYtem will show only ControlD DOh. Even if you click on Test Upstreams then Its showing error messahe like failed to connect with Quad9. NO matter whether you use Doh, Dot, DoQ. It is happening with Quad 9 only

### Expected result

Quad 9 should work

### Actual result

Test connction show, failed to connect with Quad 9

### Additional information and/or screenshots

_No response_