Instant Crash/Hang at Sign-In After Latest Update (RX 7800 XT, Steam)

Since the most recent Marathon update, I can no longer log into the game.

Behavior:

• Launch Marathon through Steam.

• Reach the title screen successfully.

• Click "Continue" to sign in.

• Game either:

  • Hangs during sign-in and becomes unresponsive, or

  • Displays error code YAM (for example, YAM 0:41) and then eventually hangs/crashes.

System:

• Steam version

• AMD Radeon RX 7800 XT

• Windows 11 (Build 26200)

Important: Marathon worked normally on this exact PC before the latest update.

Troubleshooting already attempted:

• Verified game files in Steam.

• Uninstalled and reinstalled Marathon.

• Uninstalled and reinstalled BattlEye.

• Performed a clean reinstall of AMD Adrenalin drivers.

• Disabled Hardware-Accelerated GPU Scheduling.

• Disabled Windows Defender Firewall.

• Disabled Windows Virus & Threat Protection.

• Rebooted multiple times.

• Destiny 2 and other games run normally.

Relevant logs:

• Reliability Monitor reports multiple LiveKernelEvents during Marathon sign-in attempts.

• Event Viewer shows:

  • Event ID 1002 (Application Hang)

  • Marathon.exe

  • HangType: Top level window is idle

This appears to be related specifically to the login/authentication process introduced or changed in the latest update, as the game previously worked without issue and other users appear to be reporting similar sign-in crashes/hangs after the update.

Has Bungie identified a known issue with Steam users, AMD GPUs, or the current update that could cause Marathon to hang or crash during authentication?