qBittorrent downloads remain inactive with gluetun VPN setup in Docker

[RocketPeace]

Description:
I'm running qBittorrent and gluetun on Docker Desktop with the following configuration, but my downloads stay inactive (no data transfer depite functional trackers and some peers connecting):

• Network: vpn_net (bridge-based)
• Gluetun container: image qmcgaw/gluetun:latest
• qBittorrent container: image lscr.io/linuxserver/qbittorrent:latest
• qBittorrent network mode: service:gluetun
• VPN provider: Proton VPN (OpenVPN credentials)
• VPN server: french P2P
• Using gluetun API to retrieve forwarded port
• Forwarded port is written directly into qbittorrent.conf
• Port listening seems successful
• Network connectivity seems successful
• Ping tests seem successful
• No local or network firewall seem to be blocking traffic
• Torrent features such as DHT, PEX, and LSD are enabled and tested
• Logs from both qBittorrent and gluetun show no errors or warnings

Despite this, qBittorrent downloads remain stuck inactive.
If you have additional network or connectivity tests I can run (preferably with PowerShell), please share them so I can diagnose further.

Thanks in advance for your help!

My docker-compose.yml:

networks:
  vpn_net:
    external: true

services:
  gluetun:
    image: qmcgaw/gluetun:latest
    container_name: gluetun
    cap_add:
      - NET_ADMIN
    environment:
      - VPN_SERVICE_PROVIDER=${VPN_SERVICE_PROVIDER}
      - OPENVPN_USER=${OPENVPN_USER}
      - OPENVPN_PASSWORD=${OPENVPN_PASSWORD}
      - SERVER_COUNTRIES=${SERVER_COUNTRIES}
      - VPN_PORT_FORWARDING=${VPN_PORT_FORWARDING}
      - VPN_TYPE=${VPN_TYPE}
      - API_ENABLED_GLUETUN=${API_ENABLED_GLUETUN}
      - API_HTTP_GLUETUN=${API_HTTP_GLUETUN}
      - API_KEY_GLUETUN=${API_KEY_GLUETUN}
      - API_ADRESS_GLUETUN=${API_ADRESS_GLUETUN}
      - API_AUTHENTIFICATION_GLUETUN=${API_AUTHENTIFICATION_GLUETUN}
      - API_PORT_GLUETUN=${API_PORT_GLUETUN}
      - DNS_ADDRESS=***.*.*.*
      - DOT_PROVIDERS=cloudflare
      - DOT_LISTEN_ADDRESS=*.*.*.*:**
      - BLOCK_MALICIOUS=off
      - BLOCK_SURVEILLANCE=off
      - BLOCK_ADS=off
      - TZ=${TZ}
    volumes:
      - ${GLUETUN_CONFIG}:/gluetun
    networks:
      - vpn_net
    ports:
      - "8000:8000"
      - "53:53/udp"
      - 8080:8080
      - 6881:6881
      - 6881:6881/udp
    restart: unless-stopped

  qbittorrent:
    image: lscr.io/linuxserver/qbittorrent:latest
    container_name: qbittorrent
    environment:
      - PUID=${PUID}
      - PGID=${PGID}
      - TZ=${TZ}
      - WEBUI_PORT=8080
    volumes:
      - C:/path/to/qbittorrent/config:/config
      - F:/Téléchargements:/downloads
    network_mode: "service:gluetun"
    restart: unless-stopped

My qbittorrent.conf:

[Application]
FileLogger\Age=1
FileLogger\AgeType=1
FileLogger\Backup=true
FileLogger\DeleteOld=true
FileLogger\Enabled=true
FileLogger\MaxSizeBytes=66560
FileLogger\Path=/config/qBittorrent/logs

[AutoRun]
enabled=false
program=

[BitTorrent]
Session\AddTorrentStopped=false
Session\DHT=true
Session\DefaultSavePath=/downloads/
Session\DisableAutoTMMByDefault=false
Session\Encryption=2
Session\ExcludedFileNames=
Session\GlobalMaxRatio=0
Session\GlobalMaxSeedingMinutes=0
Session\LSD=true
Session\PeX=true
Session\Port=port-fowarded-given-by-gluetun-API              #changes anytime I restart Gluetun container
Session\QueueingSystemEnabled=true
Session\SSL\Port=33278
Session\ShareLimitAction=Stop
Session\TempPath=/downloads/incomplete/
Session\UseAlternativeGlobalRateLimits=false

[ConnectionLimits]
GlobalMaxConnections=500
GlobalMaxUploadSlots=30
MaxConnectionsPerTorrent=100
MaxUploadSlotsPerTorrent=6

[Core]
AutoDeleteAddedTorrentFile=Never

[LegalNotice]
Accepted=true

[Meta]
MigrationVersion=8

[Network]
Cookies=@Invalid()
PortForwardingEnabled=true
Proxy\HostnameLookupEnabled=false
Proxy\Profiles\BitTorrent=true
Proxy\Profiles\Misc=true
Proxy\Profiles\RSS=true

[Preferences]
Advanced\RecheckOnCompletion=false
Connection\PortRangeMin=6881
Connection\UPnP=false
Downloads\AppendExtension=true
Downloads\DeleteTorrentFile=true
Downloads\ExportDir=
Downloads\PreAllocateAll=true
Downloads\SavePath=/downloads/
Downloads\TempPath=/downloads/incomplete/
Downloads\TorrentExportDir=
Downloads\TorrentImportDir=
General\Locale=fr
MailNotification\req_auth=true
Queueing\IgnoreSlowTorrents=true
Queueing\MaxActiveDownloads=10
Queueing\MaxActiveTorrents=20
Queueing\MaxActiveUploads=10
Queueing\QueueingEnabled=true
WebUI\Address=*
WebUI\CSRFProtection=false
WebUI\ClickjackingProtection=true
WebUI\HTTPS=false
WebUI\HostHeaderValidation=false
WebUI\LocalHostAuth=false
WebUI\Password_PBKDF2="*****"
WebUI\Port=8080
WebUI\RootFolder=/
WebUI\ServerDomains=*
WebUI\UseUPnP=false
WebUI\Username=*****

[RSS]
AutoDownloader\DownloadRepacks=true
AutoDownloader\SmartEpisodeFilter=s(\\d+)e(\\d+), (\\d+)x(\\d+), "(\\d{4}[.\\-]\\d{1,2}[.\\-]\\d{1,2})", "(\\d{1,2}[.\\-]\\d{1,2}[.\\-]\\d{4})"

[Speed]
ApplyRateLimitToPeers=true
ApplyRateLimitToTransport=true
ApplyRateLimitToUTP=true
DownloadLimitAlt=0
GlobalDownloadLimit=0
GlobalUploadLimit=0
UploadLimitAlt=0