open vpn problems: cannot resolve host

[Orangeday]

Hey there,

every morning at around 3 am, my internet stops working. When I look into the logfiles, this is displayed:

Mar 23 11:27:16 openvpn[1258]: SIGUSR1[soft,init_instance] received, process restarting
Mar 23 11:27:18 openvpn[1258]: WARNING: No server certificate verification method has been enabled. See http://openvpn.net/howto.html#mitm for more info.
Mar 23 11:27:18 openvpn[1258]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Mar 23 11:27:33 openvpn[1258]: RESOLVE: Cannot resolve host address: swiss.privateinternetaccess.com: Name or service not known
Mar 23 11:27:48 openvpn[1258]: RESOLVE: Cannot resolve host address: swiss.privateinternetaccess.com: Name or service not known
Mar 23 11:28:08 openvpn[1258]: RESOLVE: Cannot resolve host address: swiss.privateinternetaccess.com: Name or service not known
Mar 23 11:28:28 openvpn[1258]: RESOLVE: Cannot resolve host address: swiss.privateinternetaccess.com: Name or service not known
Mar 23 11:28:48 openvpn[1258]: RESOLVE: Cannot resolve host address: swiss.privateinternetaccess.com: Name or service not known
Mar 23 11:29:08 openvpn[1258]: RESOLVE: Cannot resolve host address: swiss.privateinternetaccess.com: Name or service not known

I set everything up exactly like it's told in the PIA description for merlin. Any idea why I have to stop the VPN client every 24 and restart it again to make it work again?
This is inside my custom configuration:
persist-key
persist-tun
tls-client
verb 1
remote-cert-tls server

Router: Asus AC56U