Full diagnosis + fix for "Unknown error during upload" on large files:
root cause is browser DNS-over-HTTPS bypassing LAN DNS -> Cloudflare mangles
the parallel chunk stream. Server/DNS already correct (Technitium+UniFi return
internal .185). Fix = disable browser DoH (.reg/PowerShell/GPO included).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
tommy