java - Different behavior on ubuntu and windows using libgdx -

i'm trying develop simple client / server game. server stores players data , sends them when requested or when data changes (player position, name etc) while client displays players connected server. graphic aspect simple: square representing player can move in 2d.

i'm running server , client on ubuntu, while other client runs on windows. noticed when move windows player corresponding square moves smoothly on ubuntu side, while when move ubuntu square there lag when windows displays other pc's player.

i thought happened because of bad connection or poor server optimization, because smoother client 1 running on same machine of server.

but noticed if move both windows , ubuntu player, lag disappears , movement become smooth on both sides.

this main method on client:

public void render () {     if(updatelistneeded && islogged) { //if game started update players list         client.requestlist();         updatelistneeded = false;     }     player.update(); //move player flags triggered arrow keys , getdeltatime()     gdx.gl.glclearcolor(0, 0, 0, 1);     gdx.gl.glclear(gl20.gl_color_buffer_bit);     batch.begin();     color c = new color(batch.getcolor());     batch.setcolor(player.getgdxcolor());     batch.draw(playsprite, player.getx(), player.gety());      list<user> users = client.getdatamanager().getallusers();     if(users.size() > 0)      (user u : users) { //display users         batch.setcolor(u.getgdxcolor());         batch.draw(playsprite, u.getx(), u.gety());     }     batch.setcolor(c);     batch.end(); } 

what can do?