Issue with OpenVpn after FW enabled

Hey all,

Bit of a newbie here.

I have just set a VPS running OpenVPN. I have installed it via wget https://git.io/vpn -O openvpn-install.sh && bash openvpn-install.sh
Set it to use 443 in install options

All works fine on my client PC using Viscosity client but when I enable the firewall on the VPS - gets stuck at the TLS error below.

I have added TCP and UDP authorise port 443
Client uses UDP as per defaults

Getting TLS error: Key negotiation failed
TLS handshake failed

In the trace , is it not listening properly on 443 ?
Do I need another port open?

Thanks

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.53:53 0.0.0.0:* LISTEN 627/systemd-resolve
tcp 0 0 0.0.0.0:5999 0.0.0.0:* LISTEN 793/sshd
tcp6 0 0 :::5999 :::* LISTEN 793/sshd
udp 0 0 127.0.0.53:53 0.0.0.0:* 627/systemd-resolve
udp 0 0 IP removed:68 0.0.0.0:* 614/systemd-network
udp 35328 0 0.0.0.0:443 0.0.0.0:* 738/openvpn

To add: I have made the config in the OVH Firewall Network and haven't used iptables. I attach a SS.

!rules|690x305