Tunnel dropping to Smoothwall

[samdel567]

Hello!, We are having an intermittent issue between a Smoothwall and PFsense.

The IPSEC tunnel comes up and works for its designated lifetime Phase 1 (8 hours / 2 hours - changed to assist logging)
It works fine in the day but requires re-dialing every morning from the Smoothwall side, I have setup a continuous ping behind the PFsense to an IP across the VPN which is responding happily so whilst its only a small amount of packets its still packets!
As an added another tunnel is up working to a Fortinet on the same PFsense without drops so its this tunnel only and to throw a curve ball in the Smoothwall has 13 other tunnels up to other devices none of which require re-dialing
Pfsense version 2.3.5 release P2
Smoothwall S8 (latest configuration)
Phase 1 - IKEV1 - IPV4 - Mutual PSK - Main - AES256 - SHA1 - DH14 - 7200 lifetime - Rekey disabled - DPD enabled
Phase 2 - Tunnel IPV4 - LAN to Network (/8) - ESP - AES256 - SHA1 - DH14 - 3600 lifetime - ping host in range and responding
Traffic allowed across tunnel

If anyone has a working configuration for PFsense to S8 please let me know

Appreciate the help!

Thanks
Sam