Try this.
Index: java/org/l2jmobius/gameserver/geoengine/GeoEngine.java
===================================================================
--- java/org/l2jmobius/gameserver/geoengine/GeoEngine.java (revision 9585)
+++ java/org/l2jmobius/gameserver/geoengine/GeoEngine.java (working copy)
@@ -645,7 +645,7 @@
int z = block.getHeight(index);
// Perform sine of sight check (next cell is above line of sight line), return fail.
- if (z > losz)
+ if (!canMove && (z > losz))
{
return false;
}