So I am experiencing a similar issue with Solarwinds not receiving Netflow or Syslogging, Through packet captures thou it appears that if you have multiple vlans configured the MX is not using the native vlan as the source. Once i removed all other vlans from the site to site vpn, i started to see netflow traffic and syslog messages. Is there something I can do on the dashboard to correct this behavior so netflow and syslogging are being sourced from the native vlan?