Random Application disconnection over route based VPN tunnel migrated from FG60C to FG90D

[yugandhar206]

Hi,  We have recently migrated from Fortiwifi60C (4.00-FW-build672-130904 - Policy VPN) to FG90D(5.2.2 - Route VPN). After the migration we are facing random application disconnection particularly on one VPN. There were no changes in VPN parameters and SA life times except changed from Policy VPN to Route VPN. Run the Wireshark on the client machine and it is showing TCP out-of-order packet, TCP packet re-transmission and finally reset the connection.But VPN tunnel is showing UP.

Can anyone help me to troubleshoot the issue.

Regards,

Yugandhar