After configuring openvpn with selective routing - DHCP stops working

[trip5ter]

Hi,
Hoping someone can assist me.

Im running an RT-AC66U with firmware 378.54_2 and As soon as I've configured an openvpn client connection to a server with some selective routing i have been experiencing some weird behaviour from dhcp.

I have wired connections, and 2 SSIDs (the main SSID and a guest one which has full access to lan)configured on the router.

when the vpn is configured I can only get a ip address from the guest network, however if take a longer time for this to happen.

please advise where i should start with this one?

regards
trip5ter