This has happened to me once... The game would let me sprint by double tapping W, but by default I was not allowed to "jog". Single tapping left shift and double tapping left shift didn't fix the issue. Also I had tried swapping items/weapons, aiming and bringing down aiming via space bar. With no items in hand and my 'ready' stance toggled off, it didn't change. Second mouse button didn't fix issue either. Was literally stuck in walk mode standing up. But yes I could still sprint and squat walk. But no normal jog. Happened to me around Stary Sober yesterday. Fixed by disconnecting and reconnecting to server