Summarize this now:

1. OpenVPN will disconnect after a while.

2. Performance is not expected. Like what you reported: https://community.tp-link.com/en/business/forum/topic/596196?replyId=1296198

Persists till now? 20Mbps or so? What is your upload and download speed? ISP plan.
3. IPsec and SSL would not work at the same time.

 

Do I understand you correctly?

 

Let me ask you this about the last one, did you bring up #3 in the past when you contacted us about OpenVPN? I recall I have met this and the dev told me they didn't reproduce this. It was because your network with too many VPN tunnels.

Do you reproduce this in two routers without too many variables?

  @Clive_A 

1  VPN stop communicating again after added keepalive 10 120.

Router show connected and OpenVPN server show connected but no ping or other fun in the tunnel.

2 Performance is no about 80-100 Mbps so much better, Unifi UXG-PRO do 200 Mbps or more, 200Mbps limit is problably server limit.

3 I have the config I have so I haven't tested anything with less configuration, there are some Ipsec VPNs about 25 but only 6 are enabled.

I have no active  L2TP PPTP or OpenVPN exept OpenVPN that I test just now, normaly disabled.

But SSL VPN is not a big deal for me, I don't use this but others may want to use SSL