Can confirm the same root cause on my end — my Windows username was in Chinese (non-ASCII), causing the exact same CTD (STATUS_STACK_BUFFER_OVERRUN) on loading into multiplayer servers, both official and private, on 2.22. No mdmp was generated either, matching this report.
After creating a new Windows account with an English-only username (so the profile path no longer contains non-ASCII characters), the crash is completely gone.
This confirms it's not Korean-specific — any non-ASCII character in the Windows username/filepath (e.g. C:\Users\<name>\AppData\Local\Arma 3\...) seems to trigger it. Hope this helps narrow down the exact code path.