Unable to connect to server

[Tuzhii]

So. I tried joining on 1.13.2 optifine, got the message 'disconnected'. Tried to join on 1.12.2, got in for a millisecond, then got java.ioexception an existing connection was forcibly closed by the remote host. I've looked around at other posts on the forum and honestly I'm feeling kind of hopeless.
-Render distance has been decreased to 7
-Cleared server resource pack folder
-Allocated more RAM to my saves
-Tried ver 1.12.2,1.13.2,1.16.4
-Resourcepack folder is completely clear (which I'm not sure if its good or bad.)

I'm using a desktop computer that's connected to the router and honestly it rarely has problems but if all fails I'll try to restart my router later on.

 

[Tuzhii]

So. I tried joining on 1.13.2 optifine, got the message 'disconnected'. Tried to join on 1.12.2, got in for a millisecond, then got java.ioexception an existing connection was forcibly closed by the remote host. I've looked around at other posts on the forum and honestly I'm feeling kind of hopeless.
-Render distance has been decreased to 7
-Cleared server resource pack folder
-Allocated more RAM to my saves
-Tried ver 1.12.2,1.13.2,1.16.4
-Resourcepack folder is completely clear (which I'm not sure if its good or bad.)

I'm using a desktop computer that's connected to the router and honestly it rarely has problems but if all fails I'll try to restart my router later on.

By the way, I have no problems connecting to other servers.