How to enable DNScrypt when VPN is also enabled on the router?

I have an Asus RT-AC56 with a built-in VPN client.

If I enable DNScrypt first on my computer THEN enable the router VPN client, everything is fine, I have Internet connection and I am using the selected DNS server.

BUT if I try to enable DNScrypt while the VPN is working, I have no Internet connection. If I disabled the VPN for few seconds than re-enable it again, I have Internet connection and the DNS is still the selected one.

I wonder if there is a trick to enable DNScrypt whlle leaving my VPN always enabled.

Ron