Troubleshoot VPN issues on Android

I'm using the Always-on VPN feature of Android to ensure a VPN connection. Whether I'm using OpenVPN or Strongswan as a client I always have connection issues on Android if the network node changes. Either I have to wait for a random time (1min - 30min) until it works by itself or I have to reconnect manually. Strongswan is worse than OpenVPN because it literally happens every single time the node changes. Sometimes the client even reconnects by itself, as I can see on the elapsed time being reset, but I still have to reconnect manually afterwards to use the network. This is really annoying but I have no idea how to troubleshoot this problem. I tried searching CatLog for VPN entries but I didn't found any warnings or errors. How could I troubleshoot issues like that?