What are the utilities for attacking the Openvpn network, can they be identified on the local network through Wireshark?

Question

openvpn

There are several Zyxel Keenetic(2) home routers, there are clients that connect via WiFi to the local network of each of the routers (each router has its own DHCP + netmask). Both routers are connected to TP-LINK941 which gives them a WAN channel.
There are users on the network who need to voluntarily-compulsorily connect to the openvpn server.
Periodically, when the load on the local network increases, when connecting to one of the routers, there are problems with openvpn, which manifest themselves in packet loss in Wireshark and the inability to connect to the VPN.
A number of questions arise:

1. How to localize the problem of losing connection with the openvpn server?
   
2. How to check if this problem is related to the Internet provider (maybe it's worth letting vpn traffic on 80 (http port))?
   
3. How to check that the problem is not in TP-LINK?
   
4. How to check that the problem is not in the Openvpn server\client, what logs should I look at? I looked at the system logs, looked at the openvpn server logs - empty. It seems that the connection does not disappear, but the traffic simply stops going through the VPN channel.
   
5. How to check that this is not someone's playful pens, are there such utilities and can they be identified on the local network via Wireshark?
   

Answer 1

OpenVPN works much better over UDP than over TCP, especially when the connection quality is poor.