Unable to establish VPN connection to my PiVPN (ovpn) from my Asus RT-AC86U running Asuswrt-Merlin 386.14

[B0GDAN]

Hello all,

I've set up PiVPN on my RPi4 and set it up to run as an OpenVPN server. While my clients run ok on Windows and Android I can't say the same about the VPN client of my Asus router.
The errors I get are the following and the router asks me to check my config (Error - check configuration!)

Oct 27 20:13:41 ovpn-client4[30344]: ++ Certificate has EKU (str) TLS Web Server Authentication, expects TLS Web Server Authentication
Oct 27 20:13:41 ovpn-client4[30344]: VERIFY EKU OK
Oct 27 20:13:41 ovpn-client4[30344]: VERIFY X509NAME OK: CN=xxx
Oct 27 20:13:41 ovpn-client4[30344]: VERIFY OK: depth=0, CN=xxx
Oct 27 20:14:41 ovpn-client4[30344]: TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
Oct 27 20:14:41 ovpn-client4[30344]: TLS Error: TLS handshake failed
Oct 27 20:14:41 ovpn-client4[30344]: SIGUSR1[soft,tls-error] received, process restarting
Oct 27 20:14:41 ovpn-client4[30344]: Restart pause, 1 second(s)
Oct 27 20:14:42 ovpn-client4[30344]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Oct 27 20:14:42 ovpn-client4[30344]: TCP/UDP: Preserving recently used remote address: [AF_INET]xxx:1194
Oct 27 20:14:42 ovpn-client4[30344]: Socket Buffers: R=[524288->524288] S=[524288->524288]
Oct 27 20:14:42 ovpn-client4[30344]: UDPv4 link local: (not bound)
Oct 27 20:14:42 ovpn-client4[30344]: UDPv4 link remote: [AF_INET]xxx:1194
Oct 27 20:14:42 ovpn-client4[30344]: TLS: Initial packet from [AF_INET]xxx:1194, sid=8aa186d7 ed501b60
Oct 27 20:14:42 ovpn-client4[30344]: VERIFY OK: depth=1, CN=Easy-RSA CA
Oct 27 20:14:42 ovpn-client4[30344]: VERIFY KU OK
Oct 27 20:14:42 ovpn-client4[30344]: Validating certificate extended key usage

So far all I did was import the ovpn file and set the service state to on.
Would like to mention that everything appears to be working fine with the Softether VPN server, also configured as OpenVPN.
Can you help me debug my config?

Thanks
Bogdan