[GAMEPLAY] Rek'sai's W Bug on Fiddlesticks

Rek'sai cannot unburrow Fiddlesticks after she used E to approach him. It happened twice in one game. The first time was Fiddlesticks drained to me and I used E to approach him, then I right clicked him but I cannot unburrow and cannot attack. I am not sure the situation of the second time, it seemed that I E on him and he didn't drain to me, and I cannot unburrow again.