Seamless Tunnel and sharing VPN connection

[nicobar]

Hello,

I am having two distinct problems with the client:
- Checking Seamless Tunnel kills the connection: no navigation, no websites, nothing works.
- sharing the VPN connection does not work reliably

My setup:

- Router Asus RT-AC68P at home, latest firmware, fast and reliable internet connection, public IP with dyndns, router configured as OpenVPN server
- Computer A: personal Windows 10 laptop connected to WiFi somewhere else than home, running latest VPN Client, and sharing the connection via hotspot; alternatively, I have the Private Internet Access (PIA) paid VPN subscription and PIA client which I can also share via hotspot
- Computer B: work laptop with Windows 10 near computer A, nothing can be installed or configured as I am not admin

My goal: from Computer B, near computer A, anywhere I am with a WiFi connection, it needs to look like I am at my home. WhatismyIP should return the home public IP. In case of VPN disconnection, even brief, internet traffic should be killed by the Seamless Tunnel option (PIA client also has an equivalent option)

Where I stand:
- I computer A, when I turn on the OpenVPN client, I do get the home public IP. I can also ping devices inside my home LAN. But when I turn on the seamless tunnel option, nothing works anymore, no internet. I turn it off and it comes back again. When the client is connected, it does not show disconnections or like it's trying to reconnect, it looks ok to me.
- When I share the OpenVPN connection via hotspot to computer B, (seamless tunnel switched off otherwise it does not work) the connection is unreliable: computer B may get or may not get internet, certain websites work and others do not, and IP may be the one of the home or not. Unreliable.
- When I instead share the PIA connection from computer A, everything works perfect! Fast, reliable, whatismyip in computer B gets whatever PIA IP I chose in computer A.

So I think there may be some misconfiguration and I hope somebody here may give me some hint?

My ovpn file:
remote XXXX.dyndns.org 1194
float
nobind
proto udp
dev tun
sndbuf 0
rcvbuf 0
keepalive 15 60
comp-lzo adaptive
auth-user-pass
client
auth SHA1
ns-cert-type server

My Asus configuration (not sure how to add a picture here!):
Server port 1194
RSA Encription 1024
Client will use VPN Access: "Internet and Local Network" is selected ("Local network only" is the other option)
Interface Type: TUN
Protocol: UDP
Respond to DNS: Yes
Advertise DNS to clients: Yes
Encription cipher: Default
HMAC Authentication: SHA 1
Compression: Adaptive
Username / Password Auth Only: No
Authorization Mode: TLS
Extra HMAC Authorization: Disable
VPN Subnet / Netmask: 10.8.0.0 --> 255.255.255.0
Push LAN to Clients: Yes
Direct Clients to redirect Internet Traffic: Yes
TLS Renegotation time: -1 seconds
Manage Client-specific Options: No


Thank you so much!

[TinCanTech]

Which version of openvpn is that ?

[nicobar]

the client version is 3.3.4 (2600)