NetworkManager - OpenVPN connects, but no access to the Internet

Question

This happens only with this exact OpenVPN connection, only on this machine and only with NetworkManager. Regardless whether i connect to the VPN via command-line or NetworkManager itself. If i establish the Wi-Fi or Ethernet connection in some other way (dhcpcd or netctl), OpenVPN works just fine. I went as far as reinstalling the whole OS itself, didn't help.

client.conf

client
dev tun
proto udp
sndbuf 0
rcvbuf 0
remote vpn-ip 443
resolv-retry infinite
nobind
persist-key
persist-tun
remote-cert-tls server
auth SHA512
cipher AES-256-CBC
comp-lzo
key-direction 1
verb 3
redirect-gateway def1
up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf
push "dhcp-option DNS 208.67.222.222"
push "dhcp-option DNS 208.67.220.220"
(certificates)

ip route

default via 10.188.0.1 dev wlp2s0 proto dhcp src 10.188.183.56 metric 303 
10.188.0.0/16 dev wlp2s0 proto dhcp scope link src 10.188.183.56 metric 303

ip route after connecting to the vpn

default via 10.8.0.1 dev tun0 proto static metric 50 
default via 10.188.0.1 dev wlp2s0 proto dhcp src 10.188.183.56 metric 303 
10.8.0.0/24 dev tun0 proto kernel scope link src 10.8.0.2 metric 50 
10.188.0.0/16 dev wlp2s0 proto dhcp scope link src 10.188.183.56 metric 303 
10.188.0.0/16 dev wlp2s0 proto kernel scope link src 10.188.183.57 metric 600 
10.188.0.0/16 dev wlp2s0 proto kernel scope link src 10.188.183.56 metric 600 
10.188.0.1 dev wlp2s0 proto static scope link metric 600 
vpn-ip via 10.188.0.1 dev wlp2s0 proto static metric 600 

I've tried all kinds of things, and I honestly don't know what to do. For now i'm using wicd as a workaround, and it's working fine. I'm on Arch Linux, in case it helps. What do you think is the problem?

UPD: it seems to work if i change the protocol to TCP on both the server and the client. Going to investigate further.