Ac56U on Merlin .55 routing all clients to vpn issue

Hi,

I'm using a VPN 2 x client setup with policy rules splitting the clients up between ISP and VPN, however this only works for a few days as all my clients suddenly become routed to the VPN and I have to reboot the router to fix the issue.

Any ideas what could be causing this?

@RMerlin

Thanks.