Use skript-worldguard

mirricraft-speed.sk

@@ -45,10 +45,10 @@ command /speed [<text>] [<number>] [<player>]:
 # Lobby Tunnel
 on region enter:
     wait 1 tick
-    if "%event-region%" contains "lobby_tunnel_":
+    if "%region%" contains "lobby_tunnel_":
         set player's walking speed to 0.4
 
 on region exit:
     wait 1 tick
-    if "%event-region%" contains "lobby_tunnel_":
+    if "%region%" contains "lobby_tunnel_":
         set player's walking speed to 0.2