DoH with h3:// scheme works unstable, https:// works fine

[ammnt]

Please answer the following questions for yourself before submitting an issue

• [X] Filters were updated before reproducing an issue
• [X] I checked the knowledge base and found no answer
• [X] I checked to make sure that this issue has not already been filed

AdGuard version

7.18.1 (4778) (CL 1.15.55, DL 2.5.33 )

Browser version

Firefox 131.0 (64-разрядный)

OS version

Windows 11 23H2

Issue Details

Steps to reproduce:

1. Install AdGuard for Windows
2. Install AdGuard VPN for Windows
3. Add your own DoH server with h3:// scheme
4. Test it

Expected Behavior

DNS resolving will be more stable and faster

Actual Behavior

DNS resolving is unstable. SERVFAIL error in logs etc.

Screenshots

Screenshot 1


Additional Information

Verbose logs from app and VPN + exported settings will be sent to devteam@adguard.com

[ammnt]

Logs has been sent just now. Support ticket: 964926.

[ammnt]

Same behavior with android applications.

[ammnt]

So? Anyone?...

[sfionov]

@ammnt Issue should be fixed in the latest AdGuard VPN nightly version 2.4.1601.0