Dnsmasq spam after configuring OpenVPN client

Hello, my device is Xiaomi MiWifi mini using latest 17.01.2 firmware.
After configuring OpenVPN (router is a client) I get constant spam in logs:

Thu Jun 29 16:26:04 2017 daemon.warn dnsmasq-dhcp[1200]: no address range available for DHCP request via tun0
Thu Jun 29 16:26:20 2017 daemon.warn dnsmasq-dhcp[1200]: no address range available for DHCP request via tun0
Thu Jun 29 16:26:32 2017 daemon.warn dnsmasq-dhcp[1200]: no address range available for DHCP request via tun0
Thu Jun 29 16:26:44 2017 daemon.warn dnsmasq-dhcp[1200]: no address range available for DHCP request via tun0
Thu Jun 29 16:26:53 2017 daemon.warn dnsmasq-dhcp[1200]: no address range available for DHCP request via tun0

I tried adding list notinterface 'tun0' under config dnsmasq in /etc/config/dhcp. It didn't help. I also tried adding except-interface=eth0.2 in /etc/dnsmasq.conf - also nothing.

Any help or ideas are appreciated!