I use the keyboard to play and it works fine most of time. However, there are times when I try to walk using WASD and the character keeps stopping, as if I have lifted my finger from the key. If this keeps happening for a long time, I restart the game and it works normally again.

I really don't know what's causing this problem. I noticed that if I try to walk using the mouse, pressing both buttons, the character will move smoothly. The problem seems to affect only the keyboard.