Seems there is no solution for this.  There is no way to get a TP Link Router to only route the specific VPN network traffic and not all traffic.  

Other routers(Asus for sure) support this, kind of surprised, as it's part of the basic OpenVPN config to define the traffic being routed.  So the TP Link router is overriding what is defaulted in the OpenVPN client config.

  @JatSrt I have Archer AX3000 AX55 router, it works fine, with vpn, only added devices have the vpn and rest will be without vpn. No issues. I am using expressvpn openvpn service.  In vpn client just ammend the ovpn file from express vpn as under:

dev tun
fast-io
persist-key
persist-tun
nobind
remote (server ips or link) 1195
remote-random
pull
comp-lzo no
tls-client
route-gateway dhcp
persist-local-ip
verify-x509-name Server name-prefix
ns-cert-type server
key-direction 1
route-method exe
route-delay 2
tun-mtu 1500
fragment 1300
mssfix 1200
verb 3
#cipher AES-256-GCM
#keysize 256
auth SHA512
sndbuf 524288
rcvbuf 524288
auth-user-pass

it do take 5 to 10 minutes for establihing connection, but once connected work fine. You can only route vpn services to specified devices as required.