Emulator

Can confirm this issue

Here is my writeup

Summary

RetroAchievements login fails intermittently in standalone Dolphin with "Login failed" / no-internet-connection-style error, despite confirmed working network connectivity (DNS, IPv4, IPv6, and TLS all verified functional at the OS level at the exact time of failure). Log shows the failure is a DNS resolution timeout inside Dolphin's HTTP client, not an actual network outage.

This appears to be the same issue described in #13892.

Environment
Platform: Batocera Linux 43.1 (2026/05/28 build)
Dolphin build: Batocera-packaged standalone Dolphin, version scheme 2606 (commit pinned ~Jun 25, 2026 on batocera.linux dolphin-emu.mk; installed binary dated May 28, 2026)
Build config confirms: -DUSE_RETRO_ACHIEVEMENTS=ON, linked against system libcurl.so.4.8.0 (curl 8.12.1, OpenSSL 3.4.0, AsynchDNS feature enabled)
Backend: OpenGL (GFXBackend = OGL)
RetroArch on the same system connects to RetroAchievements without issue, using the same physical network path.
Steps to Reproduce
Launch standalone Dolphin on Batocera.
Go to Tools → Achievements.
Attempt to log in with valid RetroAchievements credentials.
Login fails, UI reports it as a connectivity/no-internet-connection style failure.
Issue is intermittent — sometimes fails with no specific reason logged, sometimes fails with an explicit DNS resolve timeout (see log below).
Actual Behavior

Console log (via View → Show Log Configuration → Write to Console, verbosity Warning, Core/Common/Achievements log types enabled) captured during two consecutive login attempts, same session:

54:57:642 Core/AchievementManager.cpp:78 I[RetroAchievements]: Attempting to log in jpiermarini (with password)
55:00:692 Core/AchievementManager.cpp:78 I[RetroAchievements]: Login failed: Failed HTTP request.
55:00:692 Core/AchievementManager.cpp:930 W[RetroAchievements]: Failed to login jpiermarini to RetroAchievements server.

56:30:209 Core/AchievementManager.cpp:78 I[RetroAchievements]: Attempting to log in jpiermarini (with password)
56:33:251 Common/HttpRequest.cpp:283 E[COMMON]: Failed to POST https://retroachievements.org/dorequest.php: Resolving timed out after 3002 milliseconds
56:33:251 Core/AchievementManager.cpp:78 I[RetroAchievements]: Login failed: Failed HTTP request.
56:33:251 Core/AchievementManager.cpp:930 W[RetroAchievements]: Failed to login jpiermarini to RetroAchievements server.
Expected Behavior

Login to RetroAchievements should succeed reliably, consistent with the fact that DNS resolution and connectivity to retroachievements.org are confirmed working via direct testing at the OS level (see diagnostics below), including tests run within seconds of a failed Dolphin login attempt.

Diagnostics Performed (all ruling out external/network causes)
curl -v --max-time 5 https://retroachievements.org/dorequest.php — succeeds instantly and reliably, every attempt, both immediately before and after Dolphin login failures.
Same test forced to IPv4 only (curl -4) and IPv6 only (curl -6) — both succeed instantly.
DNS-over-HTTPS lookups for both A and AAAA records for retroachievements.org — return immediately with valid records.
Confirmed Dolphin is dynamically linked against the exact same system libcurl.so.4.8.0 used by the successful CLI curl tests (ldd /usr/bin/dolphin-emu).
Confirmed Dolphin's process runs in the same network namespace as the shell (readlink /proc//ns/net identical).
Confirmed Dolphin's process environment is effectively identical to the shell's (no proxy variables, no DNS overrides) via /proc//environ diff.
Waited 60+ seconds after launch before attempting login, to rule out startup-time network contention — issue still occurred.
Confirmed RetroArch, on the same machine/network, logs into RetroAchievements successfully every time.

Given the above, the DNS resolve timeout appears to originate specifically from Dolphin's own HttpRequest/curl call for the RA login request, rather than from any actual system-level DNS or network issue.