How could I troubleshoot my minecraft connection to servers?

Recently I’ve tried joining a friend’s minecraft server, although it worked fine for the first few days, I suddenly stopped being able to connect properly, it lets me into the server but around 20 seconds later I get kicked with the reason java.io.IOException: Existing connection was forcibly closed by the remote host. This is constant and doesn’t seem to be affected by player presence, a VPN/no VPN, a whole different client, a clean Minecraft re-install, nothing has worked in fixing it, it working every few hundred attempts seems completely random.

This is not the first time I’ve had an issue with connecting to a small server, I’ve had some friends create servers in the past and it happened on one of them, however not on the others.

Variables I’ve collected:

• It has occured when:
  • Server is using Waterfall, Paper or Spigot.
  • Server is hosted in different regions.
  • I have attempted all of the above fixes.
  • First joining the server.
  • Being on the server for a few days.
  • Using Essentials. (This is my best guess as to the cause, I feel like it wasn’t happening before Essentials was added to the current server)
• It hasn’t occured locally.

Pinging the server in a cmd works and it pings and replies with no losses (Tried up to -n 150).

The only weird thing about my connection is that I am relying on a TP-Link adapter to bring WiFi to my room and an Ethernet cable connected to it and my computer.