SSL VPN Disconnects After 5 Minutes or Less

I setup an SSL VPN on a Sonicwall SOHO 250, running SonicOS 6.5.4.0. It connects just fine, but disconnects after 3-4 minutes.

  • Users setup with TOTP
  • VPN Timeout Changed to 60 Minutes
  • Created Firewall rule to extend TCP timeout to 120 minutes for terminal services
  • Changed user timeout to 60 minutes
  • Happens with both Netextender and Sonicwall Mobile Connect apps
  • No other custom firewall rules aside from those stated in this post

Does anyone have any ideas to fix this issue?