Apex Legends closes instantly during EA Javelin Anticheat installation loop

Title:
Apex Legends closes instantly during EA Javelin Anticheat installation loop (Steam)

Body:
Hello! After the September 29 update, I cannot launch Apex Legends on Steam.

Every time I press "Play", a short anti-cheat installation window appears, it goes to the final step, then the launcher window completely closes and nothing happens. When I try to launch the game again, the cycle repeats.

I noticed that the EA Anticheat installer keeps creating duplicate installer files with _b extensions (like EAAntiCheat.GameServiceLauncher.dll_b, EAAntiCheat.GameServiceLauncher.exe_b, preloader_l.dll_b) in the game folder every time it fails.

My steps tried:

Cleaned the Steam download cache.
Completely deleted the AC folder in Program Files\EA and EasyAntiCheat folder.
Ran Steam as Administrator and verified game files integrity multiple times.
Checked Windows Core Isolation (all features are disabled).
I do not have CryptoPro, reWASD, or third-party bypass tools installed.
OS: Windows 11 (64-bit)
Platform: Steam

The installer keeps corrupting its own files and failing at the final step. Please fix the EA Javelin installer bug.